Programmatic advertising is rapidly becoming the dominant form of media buying in the digital landscape. In fact, more than 91% of display ads in the US are expected to be purchased using programmatic methods by 2024

As advertisers increasingly turn to programmatic buying to reach their target audiences efficiently, the role of supply-side platforms (SSPs) has become paramount.

SSPs serve as a vital bridge between publishers and demand sources, automating the selling process through real-time auctions and ensuring that ad space is sold at optimal prices.

This article explores the concept of SSPs, how they function within the programmatic ecosystem, and their significance in helping publishers navigate the complexities of digital advertising while enhancing their profitability.

How does SSP work?

An SSP is a gateway for publishers to trade their advertising inventory programmatically across websites, games, or mobile apps through automated auctions. 

The primary goal of an SSP is to provide timely reporting on campaign performance while maximizing the price of ad spaces for publishers.

Here are some key functionalities it offers:

• Access to demand: Connects publishers to multiple buyers, enhancing their revenue potential.
• Market insights: Allows publishers to review market conditions and adjust pricing accordingly.
• Price control: Empowers publishers to set and manage minimum prices for their inventory.
• Yield management: Helps control fill rates and optimize overall yield from ad spaces.

As a critical component of the programmatic advertising ecosystem, an SSP enables publishers to auction off impressions to various buyers, facilitating real-time bidding. It provides a unified interface for managing ad campaigns, reviewing campaign details, and controlling CPM (cost per thousand impressions). SSPs can integrate with demand-side platforms (DSPs), agency trading desks, ad networks, and ad exchanges, allowing for seamless trading across multiple demand partners.

Once publishers set up SSP ad tags on their pages, media buying occurs automatically through real-time auctions or other programmatic methods. The SSP streamlines this process by reviewing ad requests, matching them with relevant inventory, and conducting instant negotiations.

Although inventory trading is fully automated, SSPs offer mechanisms to protect publishers from unfavorable deals. They allow publishers to establish a price floor, ensuring that auctions do not fall below a specified minimum price.

Additionally, SSPs prioritize brand safety and reputation management. They filter out spam and inappropriate ads, helping publishers maintain a loyal audience. For example, a publisher can create whitelists and blacklists to restrict specific advertisers, such as preventing tobacco and alcohol companies from displaying ads on child-oriented websites.

DSP vs. SSP

The demand-side platform, or DSP, is a point of entry for advertisers into the programmatic ecosystem. DSP is a software that allows brands, ad networks, and agencies to purchase ad spaces from publishers programmatically.

A DSP sets the advertiser’s requirements regarding the audience, price, and campaign goals. The platform automatically assesses available ad inventory and bids on the ad spaces that best meet the requirements. A DSP can also measure and optimize marketing campaigns in real-time and dynamically change creatives in the ad space.

How an SSP interacts with a DSP

• A user enters the website.
• Information about the potential impression is passed to SSP.
• SSP offers the impression to ad exchanges or directly to DSPs.
• DSP reviews the impression and analyzes if it satisfies the advertiser’s campaign settings. If it does, DSP bids on the impression, frequently through an ad exchange.
• SSP receives bids from all the demand partners and chooses the highest bidder.
• The winning ad appears on the website.

Features of supply-side platforms

Supply-side platforms (SSPs) offer a range of features designed to help publishers optimize their advertising strategies and maximize revenue 

1. Ad quality/format variety

SSPs support various advertising formats. When you contract an SSP, you can be confident that their publishers adhere to a single ad-serving protocol, and consequently, you won’t need additional adjustments to serve ad creatives.

SSPs work in various media environments: web, in-app, in-game, CTV, and DOOH. In each environment, SSPs support various ad formats: display ads, banner ads, native ads, playable, push, and video ads.

Some SSPs specialize in web advertising, mobile, and desktop traffic, and others operate exclusively in the OTT/CTV sector. However, most SSPs are trying to grasp more niche markets and reach as many environments and formats as possible.

2. Real-time transactions/bidding

SSPs are optimized in real time based on extensive publisher data. This allows marketers and advertisers to target individual impressions instead of buying blocks of advertising. The actioning model fosters the transparency of the digital marketplace and allows advertisers to get the real market value of ad placements.

Auctioning may drive up the price of specific placements, but in the long run, it is a more cost-effective strategy for advertisers than direct media buys.

3. Geographic targeting

SSPs provide information-rich geolocation data for advertisers. The precision depends on the type of device and its connection to the network. Desktop devices with fixed internet access can provide internet protocol (IP) information for geotargeting, although it is rarely accurate beyond the country level.

Geotargeting for mobile devices is distinct from targeting desktop impressions. Mobile devices can connect to the web in several different ways:

4. Located and contextualized impressions

SSPs structure data from publishers to offer better targeting options for advertisers. Publishers track customers’ habits and preferences and can offer highly contextualized impressions paired with behavioral data. For example, if a user surfs websites about open-ocean fishing, the SSP will categorize those impressions and suggest them to local fishing rod dealers.

Advertisers can set up a more cost-effective campaign by using a highly targeted inventory that contains located and contextualized impressions. There is a difference between targeting a person in a specific region and targeting fishing enthusiasts who frequently visit the local pond in that region.

Those impressions will cost more since they incorporate provider’s fees for data collection and management. Such data services are generally provided by data management platforms (DMP). SSPs partner with DMPs to better segment audiences, analyze traffic and supply impressions with more precise data. The additional costs vary depending on the provider.

SSP will appraise those impressions higher, but the advertiser can get a better reach and impact of their ads, and ultimately a higher return on investment.

5. Insights into a buyer persona

SSP adds another data dimension to offered impressions by supplying them with the exact location and context and defining buyer personas. Combining demographic data, such as gender, education, and income level, with nuances of user behavior allows advertisers to determine potential clients’ affinities and intents.

SSPs enhance offered impressions with contextual information on audience habits, movements, and preferences allowing advertisers to understand the mindset of the potential clients. Advertisers can better manage their campaigns and tailor their ads to specific segments of their audience.

For instance, if the user visits a web page of jewelry stores or high-end clothing shops and has an income of over $150k+ per year, the SSP will categorize this user as a luxury shopper and place it in the corresponding segment. SSP then offers this highly desirable segment to advertisers who sell products in this price range.

SSPs usually increase CPM for these kinds of profiles, but advertisers know who is behind an impression and its real value.

6. Privacy

Collecting data on the user’s behavior is becoming a sensitive topic. A surge in privacy legislation, such as GDPR and the CCPA, constrains the use of tracking cookies for targeting and personalizing ads. Advertisers are still working on a solution for a more sustainable and confidential data collection model. Despite this, SSP has a couple of perks that can mitigate this problem.

SSPs can build anonymous personas with publisher’s data without ever using personally identifiable information (PII). Publishers don’t need to give away personal and confidential information to increase the yield from their inventory. Instead, publishers build anonymous contextual personas based on the user’s activities. It combines demographic data with a breakdown of movements and daily activities without violating a consumer’s privacy.

A persona does not have a customer’s PII; instead, it tells more about the character and intentions of the website visitor. Personas enable the SSP to convey a lot of information about the audience to prospective buyers while keeping users anonymous and protecting their privacy.

Benefits of SSP for publishers

Understanding the key advantages of SSPs can help publishers make informed decisions that enhance their monetization strategies. Below are the top five benefits of using SSPs for publishers.

• Increased revenue: SSPs enable publishers to maximize their ad revenue by providing access to a larger pool of advertisers and demand sources.
• Inventory management: Publishers can efficiently manage their ad inventory, optimizing which ad spaces are sold and at what price.
• Real-time bidding: SSPs facilitate real-time bidding, allowing publishers to sell their ad inventory at higher rates as multiple advertisers compete for it.
• Data-driven insights: Publishers gain access to valuable analytics and reporting tools that help them understand audience behavior and optimize ad placements.
• Improved ad targeting: SSPs enhance ad targeting capabilities, ensuring that relevant ads are shown to the right audience, which can lead to higher customer engagement rates.

How publishers choose SSPs

SSP services are a crowded marketplace of companies hustling to stand out and prove their value. Publishers want to work with SSPs that partner with numerous demand partners and can help them make better decisions by sharing insights and timely reporting campaign results.

Here are the aspects publishers value the most when choosing an SSP:

• Performance: a stable source of demand and prospective revenue for different ad formats.
• Capabilities: platform UI/UX, functionality, analytics, ease of use and integration.
• Partnership: accountability, attention to the publisher’s goals and feedback, timely response.
• Vision: partner’s position in the market, reliability, innovation.

Programmatic buying methods

Through an SSP, a publisher can establish a priority and sell some of the inventory directly, reserve some for the closed marketplace of selected advertisers, and auction off the rest through real-time bidding.

Programmatic guaranteed

This method resembles direct media buys between the publisher and advertiser. The parties agree on the number of impressions and the price. Those impressions are reserved and guaranteed to a particular advertiser and not offered anywhere else. The negotiations occur automatically through an API.

Preferred deals

A preferred deal is a method of setting up primary advertising partners. The publishers first offer their inventory to the selected advertisers at a pre-negotiated price. However, a particular number of impressions is not guaranteed. If advertisers skip the chance to purchase those impressions, they are then transferred further to a private marketplace (PMP).

Preferred deals provide publishers with a great convenience: they can sell inventory directly to high-paying clients, with the option to sell it via other methods if the inventory remains unused.

Private marketplace

A private marketplace, or PMP, is an invitation-only trading platform for selected advertisers. It is frequently used by big publishers and media holdings with premium segments in their inventory. Instead of parading their inventory on the market, they sell it to a close circle of advertisers, such as luxury brands.

Ad space is bought and sold through a closed real-time auction with an exclusive number of participants. The advertiser’s DSP connects directly to the SSP in the private marketplace.

Open auctions

Open auctions/ Real-time bidding (RTB) is the broad term that sometimes includes open RTB and Header bidding and may encompass various selling methods.

At its core, real-time bidding is a way of trading advertising spaces through individual impressions through the real-time auction. The process of selling and buying occurs in the browser, server, or ad exchange that connects to publishers through an SSP and to advertisers through a DSP.

1. Publishers make the ad inventory available through the SSP.
2. Then, the SSP connects with demand partners (DSP or Ad exchange) and places a bid request.
3. Once advertisers assess the available ad inventory, they send a bid request back to the ad exchange or SSP.
4. SSP accesses the bids, filters out blacklisted and inappropriate ads, and sells the impression to the highest offer. DMP usually facilitates this process through the exchange of data and cookie matching between the demand and supply platforms.
5. After the deal is finalized, the ad server inputs the creative into the publisher’s site’s ad spot.

Transactions occur instantly within milliseconds while the web page is loading. Real-time bidding is usually an open marketplace where everybody can join without particular restrictions. Nevertheless, three distinct models define the sales dynamic: OpenRTB, header bidding, and a hybrid model.

OpenRTB

OpenRTB uses the waterfalling or daisy-chaining method, sequentially selling the publishers’ inventory and requesting one demand source at a time. Publishers run a succession of real-time auctions until all of their ad inventory is bought. Publishers then offer the inventory sequentially to the demand partners in the established order, according to their historical yield.

OpenRTB operates via the second-price auction model. The winning bidder pays the price offered by the second-highest bidder plus $0.01. 

Header bidding

Header bidding is another auction model that is gaining mainstream adoption in the industry. In header bidding, ad exchanges can bid simultaneously for the highest priority in the ad server instead of holding a separate auction for each demand partner. Header bidding uses the plain and simple first-price auction model. Not all SSPs offer header-bidding functionality.

Header bidding is becoming a new standard in the industry, while openRTB remains a practical strategy for publishers who want to prioritize a specific pool of advertisers. 

Hybrid model

There is also a hybrid model that combines features of header bidding and open RTB to deliver the maximum value of each impression. The server conducts the openRTB second-price auction and then goes on to a header bidding first-price auction. The winning bids compete in an additional auction determining the best price offer. The hybrid model increases the chances of getting higher bids and amplifies monetization.

Best supply-side platforms

The best way to streamline ad sales and optimize inventory is to use an advanced supply-side platform that incorporates the latest programmatic techniques.

Your choice of SSP depends on your specific needs and how you plan to manage and monetize your ad space.

There are several factors to consider when selecting the right SSP but to be included in this category, the platform must:

• Offer efficient inventory management tools to maximize ad revenue
• Provide access to real-time bidding and programmatic demand sources
• Deliver detailed insights and analytics to inform decision-making and strategy adjustments

*Below are the top 5 leading supply-side platforms from G2’s Fall 2024 Grid® Report. Some reviews may be edited for clarity.

1. Google Ad Manager

Google Ad Manager is a comprehensive management platform designed for publishers to efficiently manage their spaces. With features like real-time bidding, advanced targeting, and inventory control, Google AdManager helps maximize ad revenue while ensuring a smooth experience for both advertisers and users. 

What users like best:

“We use this platform daily to run numerous Google ad campaigns for different keywords and products in our eCommerce business. We allocate 30% of our advertising budget to it, and it’s a great tool if you have searchable keywords. Compared to other advertising platforms, we get the best return on investment from this one. The platform also makes it easy to track clicks, cost per click, conversions, and more.”

– Google Ad Manager Review, Brittaney F.

What users dislike:

“There are some things I don’t like about Google Ad Manager, such as its difficulty in integrating with other tools. As we use it more frequently, we find that integration becomes challenging, and we often have to use alternative methods to connect with other tools.”

– Google Ad Manager Review, Vikas P.

2. 33Across

33Across is a supply-side platform focused on maximizing ad revenue through high viewability and engagement. It offers real-time bidding and advanced ad formats like video and display and supports cross-platform monetization across desktop, mobile, and tablet. Its emphasis on quality ad placements helps publishers optimize their inventory and connect with programmatic demand.

What users like best:

“User privacy is central to 33Across because they do not save or store cookies, which builds customer confidence in using their application. Another unique feature is the ability to receive automatic advertisements for their products.”

– 33Across Review, Mitali P.

What users dislike:

– 33Across Review, Shivam S.

3. Sharethrough 

Sharethrough is an SSP that specializes in native advertising. It delivers ads that integrate seamlessly with publisher content to enhance user experience. It offers RTB, cross-device support, and a focus on sustainable advertising. Sharethrough’s approach helps publishers drive better engagement and revenue with nonintrusive, content-aligned ad formats.

What users like best:

“There are new advertising methods, like dynamic captioned videos and QR codes for connected TV (CTV). These seamless integrations are easy to activate and are unique features from a premium supply-side platform (SSP). Plus, they have the best representatives in the industry!”

– Sharethrough Review, Zachary J.

What users dislike:

“The reporting can be time-consuming to navigate and edit, requiring scheduled reports. It would be helpful to view reports within the user interface and have the option to export them to CSV.”

–Sharethrough Review, Tambra N.

4. AdSuite

AdSuite is a robust SSP that helps publishers streamline ad inventory management and maximize revenue through programmatic advertising. It supports real-time bidding RTB and multi-channel monetization across web, mobile, video, and in-app and offers advanced targeting capabilities. With its analytics and unified platform, AdSuite allows publishers to optimize their ad strategy and boost performance.

What users like best:

“My favorite feature in AdSuite is the analysis and insight tool. It clearly shows audience engagement. With AdSuite, my business is growing, and I’m receiving orders from various places online. I’m making money easily.”

– AdSuite Review, Kona Laxman D.

What users dislike:

“The mobile version could be improved. Its price point is higher than competitors, which raised concerns about long-term contracts. It also needs tagging to additional dashboards like Tableau to generate meaningful, data-driven insights. It took us four weeks to train staff and get started with the new software. Overall, the user experience and cost competitiveness of AdSuite can be improved.”

– AdSuite Review, Suresh P.

5. Automatad

Automatad is a SSP designed for publishers to maximize ad revenue through programmatic advertising. It offers features like ad management, header bidding, and integration with multiple ad networks to increase competition for inventory. 

What users like best:

“Automatad stands out for its user-friendly interface and effective problem-solving capabilities. Its advanced technologies are highly beneficial, and the customer support team is excellent at resolving any issues.”

– Automatad Review, Sai T.

What users dislike:

“While the support team is generally helpful, the response time can be slow. They often take longer than expected to fully understand and address queries.”

 – Automatad Review, Tariq I.

Let your ad space do the heavy lifting

Publishers’ widespread adoption of SSPs improves the quality of publisher-advertiser deals and enhances accountability in these relationships.

Similar to what DSPs do for advertisers, SSPs automate the redundant manual procedures prone to human error and streamline the ad-buying process for publishers. Publishers don’t have to negotiate directly with the salesperson and collect manual insertion orders. Instead, they leave the advertising to a pre-configured automated platform.

SSPs offer superior user analysis, data profiling, audience management, and segmentation options. Through SSPs, publishers can provide more detailed insights into their audience, enabling advertisers to target their ad campaigns to the most suitable viewers precisely. 

Discover publisher ad servers that can optimize your ad inventory, enhance performance, and maximize revenue.

This article was originally published in 2020. It has been updated with new information.