Do you know the difference between a Supply Side Platform (SSP) and a Demand Side Platform (DSP)? Or would you have to phone a friend?

If you answered phone a friend, you’re not alone. While SSPs and DSPs sound self-explanatory, there’s more to them than just supply and demand. Understanding what makes them different and how they work can be confusing for even the most seasoned digital advertiser.

Here’s a basic 101 breakdown of how these platforms operate and the benefits they offer advertisers and publishers.

What’s a Supply Side Platform

Supply Side Platforms (SSPs) help publishers sell digital ad impressions. Using automated auctions, publishers can sell and manage display, video, and native ad inventory for desktop and mobile.

Related Post: Good Bots, Bad Bots, and What You Need to Know

SSPs give publishers more control over their inventory. More control is appealing, especially given the risks programmatic poses (e.g. brand safety).

Related Post: Programmatic Advertising: Why We’ve Lost That Loving Feeling

SSPs offer some other sweet benefits, too. They help publishers aggregate and manage their networks and ad buyers more efficiently. Plus SSPs will help you find marketers who’ll maximize the value of the impressions you’re selling. Ca-ching!

Source: Giphy

If you’re in the market for an SSP, notable ones include AppNexus and OpenX.

What’s a Demand Side Platform

Demand Side Platforms (DSPs) automate the digital ad buying process. They reduce the need for negotiating which typically takes place between media buyers and sellers.

Instead, DSPs have access to digital ad space, placing bids in real-time across a variety of ad exchanges. This helps advertisers buy mobile, video, display, and search ads.

If you’re concerned about budget, DSPs will determine which impressions generate the most value. DSPs are programmed to help marketers find the most cost-efficient ad impressions to target the right audience for their brand or product.

Source: Giphy

In need of a DSP? Popular ones include MediaMath and DataXu.

How They Work Together

SSPs have access to website traffic from publishers. This traffic is what advertisers need access to. So, SSPs connect with DSPs to provide the traffic.

The DSP will dictate the direction of the SSP. For example, let’s say Mr. Crabs (DSP) has clients who need insurance traffic. Patrick (SSP) will solicit publishers that have traffic looking for insurance.

Source: Giphy

On a larger scale, imagine a grocery store like Acme who needs advertising from Coca-Cola, General Mills, and Heinz. Instead of Acme having to connect with each brand, they can work with a DSP like DoubleClick who has access to advertisers which include these brands and others.


Supply and Demand Side Platforms are more complex than their name implies. Now that you know the difference between them and how they work together, you can be the “phone a friend." Just make sure you answer when your friend calls.