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What is a Supply-Side Platform and the Many Ways to Use It

Jun 12, 202410 min read
Kate Novatska
Kate Novatska, AdTech Expert

Keep reading or watch Sergey Shchelkov, Sales Executive at Epom, giving a crystal-clear explanation of what an SSP is and how it increases publishers’ revenue.

Talking to people a lot? Spending time figuring out the best price for a single ad slot? Trying to get your fill rate to 100% with "bare hands"? Nah, that's totally out of fashion. Try SSP advertising — a cherished dream of a publisher.

With the digital ad spend forecast to take on two-thirds of total media spend by 2024, publishers need to know what is out there to help them capitalize on their ad spaces. Industry players seek ad campaign optimization, automation and better ROI in the tools they use for ad serving. That's the reason for a massive shift to programmatic: it accounts for 90.2% of all ad operations being handled in the US.

We're talking a lot about a DSP as the booster of your programmatic superpowers. But how about the supply side? Publishers also have tricks up their sleeves: the exact opposite of a DSP called a supply-side platform. And did you ever know that none other than a mighty ad server can also masquerade as the one?

What is an SSP?

The simplest definition of an SSP is:

A supply-side platform is an automated ad tech platform that publishers use to manage, sell, and optimize ad inventory of their mobile apps or websites.

This means that publishers can use SSP advertising to sell their online ad placements via real-time bidding (RTB) auction rather than negotiating prices directly with advertisers. Modern SSP programmatic platforms also offer a formidable toolkit for more effective inventory management and revenue optimization.

With an SSP, publishers can sell their display, video, and mobile inventory within a single dashboard and get more control over their placements than if they utilize services of ad networks or third-party monetization platforms. The primary purpose of SSP advertising is to improve the efficiency of selling ad inventory for publishers by maximizing views and ad fill rates.

How Does SSP Advertising Work?

When digital advertising first emerged, publishers would manually assign ads to their empty placements. However, as audiences on sites grew, competition for ad spaces started to heat up. As such, manual ad placement became impractical.

This is where SSPs and programmatic came in. They work together with another piece of ad tech, demand-side platforms, or DSPs (used by advertisers) based on the RTB protocol we mentioned before.

Here, an SSP platform receives a request from the user's browser when they visit the website and passes it to the DSP, enriching it with available user info. Advertisers automatically bid on this placement based on pre-set targeting options, CPMs, and optimization through a DSP. The highest bidders win the slot, and their ad is displayed on the website.

RTB auction in an SSP

RTB auction is automated and lasts mere milliseconds. Besides automation, its obvious benefit is making a publisher's ad inventory available to as many potential buyers as possible, maximizing the likelihood of selling the slot for the best price.

What You Should Remember about SSP in digital advertising:

  • SSP is a programmatic platform for automated inventory selling.
  • SSP is also used for yield optimization and inventory management.
  • SSP keeps your monetization activities under one roof.
  • SSP is based on an RTB auction.
  • SSP connects you to a multitude of demand sources at a time.
  • SSP features smart auto-optimization algorithms & detailed analytics.
  • SSP can be integrated with other ad tech tools, including data management platforms and ad servers.
  • SSP monitors consumer behavior on the website using pixels and fingerprints.
  • SSP supports both header bidding and RTB based on tags.
  • SSP advertising is associated with higher transparency rates compared to vertical ad networks.

DSP vs. Ad Exchange vs DMP vs. SSP: Platform Comparison

As mentioned above, SSPs work with other forms of ad tech. DSPs and ad exchanges are other key platforms in the process of programmatic buying and selling digital ads. But how do they all differ?

Demand-side platform Supply-side platform Ad exchange Data management platform
Advertiser's tool for programmatic media buying Publisher's tool for programmatic media selling Digital marketplace, a middle link in programmatic Tool for storing data and using it for better targeting

Ad Exchange vs. DSP

Ad exchanges need data on advertisers to know which bidders qualify for a publisher's website and match their audience. They pull this information from DSPs. In turn, a DSP is used by advertisers to let an ad exchange know what their bid is and what they have to offer.


Both DSP and SSP are programmatic advertising software; it’s just that they are made for different people.

The DSP is for those who buy ads, and the SSP is for those who sell them. The DSP serves for campaign management, and the SSP – programmatic ad inventory optimization. You’ve figured that out by this point.

But who exactly does what? The demand side of programmatic isn’t limited to advertisers. There are also ad agencies; these are organizations that do advertising/marketing activities instead of the advertiser, holding their client’s interest as the highest priority.

As for ad networks, it’s more complicated. These businesses cover both the demand and supply side of programmatic advertising. Their objective is to buy ad inventory from publishers at a low price and sell it to advertisers at a markup.

Ad Exchange vs. SSP

Programmatic SSPs are used to distribute publishers' inventory among ad exchanges. The ad exchange connects the publishers with the advertisers who want to bid on their inventory.


Publishers could use their programmatic SSPs with DMPs, but they rarely do. In most cases, a data management platform is used from the demand side.

Simply put, before coming to an ad exchange, the DSP first comes to the DMP for data.

The DMP looks through its data sets and searches for users targeted by the advertiser. Upon matching, the DMP forms a Device ID for an ad exchange. The auction happens, and the advertiser gets a better audience.

Here’s how all of these connect in one simple scheme:

SSP vs. ad exchange vs. DSP

Common Features of Supply-Side Platforms

Being a real weapon of programmatic, SSP comes with a ton of nifty features that make publishers' lives easier. Some of the most critical include:

  • RTB bidder

RTB allows multiple advertisers to participate in auctions for ad spaces at the same time. Advertisers all put in their highest bid without seeing what other advertisers are bidding and the highest bidder wins. This one’s a no-brainer, since the benefits of programmatic are simply locked without RTB.

  • Analytics and reporting

When using SSP for digital advertising, publishers can create and view reports regarding the performance of their ad inventory. The data includes things such as clicks, impressions, and more. This data can be used to show the success of their ad spaces and entice more advertisers to bid in the future.

  • Smart optimization

Optimization features of SSPs help publishers increase revenue. They can target fill rates, manage yield, and maximize eCPMs. Most SSP advertising platforms even have soft and hard flooring. That means that the SSP can take part in 2nd price auctions and receive higher bids as a result.

  • Cross-device inventory management

Publishers can manage all inventory types with SSP advertising, such as display, video, and mobile. They can blacklist advertisers, block certain ad content types, and much more to help ensure their campaigns run smoothly.

  • Header Bidding

Essentially, header bidding is a technology that allows publishers to offer their ad inventory programmatically before selling it directly.

The main point is having more sources of demand and, as a result, getting the highest bid for the placement. There are many ways to implement header bidding, but the usual client-side approach is a piece of cake to use. All you have to do as a publisher is add a js wrapper of a service provider.

Benefits of a Supply-Side Platform for Publishers

Some of the main ways publishers can benefit from using an SSP for digital advertising include:

  • Access to a vast range of advertisers

Programmatic SSPs can connect to multiple ad exchanges and DSPs. This allows publishers to reach far more potential advertisers in less time than while looking for partners directly.

  • Higher fill rates

Due to the high number of advertisers publishers can reach through their SSP platforms, there is a much higher chance of inventory being filled. Less vacant spaces are better for the publishers' bottom line, and the SSPs optimization also helps ensure that spaces are sold for the best value.

  • Flexible price management

SSPs offer publishers the flexibility to determine their floor price. Thus, advertisers won't be able to bid less than a set floor price, and the slot will always be sold for the appropriate value.

  • Higher monetization revenues

The combination of header bidding, price flooring, and all of the optimization features mentioned above allows publishers to reach the highest offers possible for their ad inventory. SSP advertising isn’t free, but it saves publishers a lot of money in the long run.

What Are Examples of SSPs?

Since we’re not an active SSP provider, we can’t make a detailed pros & cons section like we did with our DSP platform examples. What we can do, however, is to ask our fellow publishers, analyze the online reviews, and deduce which SSP platforms deserve your attention.

SSP: Epom’s Top

Here’s what we’ve come up with:

  • Google Ad Manager

Whether it’s a DSP, DMP, or SSP platform – Google has a service for everyone. Technically, an ad manager is a combination of an ad server, ad exchange, and ad network providers that work like a programmatic SSP. It’s a great (and popular) platform for beginners since the whole ad tech stack is covered, but it has its own issues.

Specifically it comes down to transparency and limited demand options. Fun fact – this drawback was the initial reason for the birth of header bidding.

  • Adform

The depth of analytics and optimization tools is why we’ve added Adform to our best DSP list. It has great ad-quality scanning features and is quite transparent.

As for the drawbacks, it’s almost the same as with DSPs. There’s no free trials, it’s confusing to use at first and the UI is just too complex and overwhelming.

  • Adsuite

We’ve added AdSuite, because despite a relatively small team, they get the highest praise for professionalism and compassion when it comes to customer service. Overall, this programmatic SSP has an extensive list of features and does its job automation just right.

The drawbacks are predictable at this point. The UI/UX feels like something from 2009. Everyone decides how frustrating it is for themselves.

  • Bidscube

This programmatic SSP is yet another familiar name for those who’ve read our DSP top. Bidscube’s SSP is a relatively new product. It has smooth integration and vast features, but, as always, it is not the best UI design.

The reason why we’ve added Bidscube is to show that white-label SSP platforms are becoming the new trend. Speaking of which…

What is a White-Label SSP?

A white-label product is software created by one company but intended for resale. Other brands can purchase it and rebrand it as their own. For white-label SSP platforms, this means that publishers can forego the cost and time of developing their SSP and buy a tried and tested product from an established ad tech company.

The main difference from a self-serve programmatic SSP is that it eliminates the hassle of using several SSPs, ad exchanges, and ad networks at a time. Publishers rely on different demand sources to increase fill rates on their inventory. A white-label SSP solves this problem.

the number of SSPs publishers use

How? A white-label SSP platform means publishers can get up and running their very own RTB platform, getting full transparency and setting up their own demand sources in no time, with little training or investment. So, instead of being torn between 5+ SSPs, you can gather all the DSPs you need in a single dashboard.

White-label SSPs often come with full support and onboarding to help you with inventory listing, DSP endpoint setups, and a basic introduction to performance optimization.


How to Use an Ad Server as an SSP?

A white-label ad server is a full-stack ad-serving platform for advertisers, publishers, and ad networks. Usually, it covers solely the direct ad-selling aspect.

However, some ad servers, like Epom white-label solution, can be used as SSP programmatic solutions, adding publisher’s placements to the supply and connecting their inventory to custom DSP endpoints.

If you’re an ad network or a publisher interested in the demand side of advertising (or having other specific needs), Epom offers a DSP + Ad Server bundle.

You should remember what a DSP is. Well, a white-label DSP is a tool used by advertisers and networks to bring their programmatic in-house. For many brands, this presents the significant advantage of removing go-betweens in the transaction and allowing them to bid on placements without markup.

Here's how an ad server and a white-label demand-side platform work together:

Ad server as an SSP

However, publishers can benefit from purchasing a white-label DSP as well, especially if they own some marketplace websites like Amazon or eBay. The advantages of using a DSP with an SSP as a programmatic bundle include:

Native Advertising Support

With full support, you can take care of your end customer by presenting user-friendly ads that organically fit with your brand content.

Targeting by Custom Parameters

It's possible to send custom targeting parameters from your ad server as an SSP to your white-label DSP. Thus, you let advertisers bid on search queries and keywords instead of using standard audience targeting.

Sophisticated Retargeting

Marketplaces might drive more traffic to their website through the advertiser's retargeting campaigns. They can run retargeting ads on other websites by connecting other SSPs as traffic sources and get extra profits by applying bid markups on these campaigns.

Direct + Programmatic Combined

Combining direct and programmatic means that you secure placements for the most credible partners. It's possible by creating advertisers in an ad server and running direct campaigns by linking the exact banner to the chosen placement. While the small advertisers can buy the remnants, competing in an RTB auction via your DSP.

Roles, Permissions, Advertiser Accounts

Every publisher can be a big boss of the system, having the Epom bundle under their belt. Create client accounts with restricted functionality from both supply and demand sides. Adjust custom permissions for each partner and enjoy them doing the most manual jobs by themselves.

What Is an SSP for You?

As you can see, there are plenty of options when it comes to SSPs. It doesn’t matter if you pick a white-label SSP platform, a self-serve one, or simply use your ad server as one; you have to remember this:

An excellent supply-side platform should be part of any successful publisher's toolkit. It will help you manage and simplify selling your ad inventory. Not only will it bring everything into one simple, user-friendly location, but it also enables you to customize and control what ads are displayed on your site, keeping the bad ads out.

Interested in taking your inventory management to the next level? Epom DSP + Ad Server WL bundle could be what you are looking for

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