What Is a Supply-Side Platform?

A supply-side platform (SSP) is advertising software that helps publishers by automatically managing and selling advertisement space on their websites and mobile applications. The supply-side platform optimizes the ads sold in order to maximize impression price and make the most money for publishers. SSPs manage the complex and changing ad-buying process, and save publishers the work of navigating ad-buying and filling ad space manually. They work in conjunction with ad exchanges, ad networks, and demand-side platforms (DSPs) to create the best solution for publishers and advertisers.


What are the main features of supply-side platforms?

SSPs are designed to make advertising simpler for publishers. Modern SSPs offer many features which take the complexity out of advertising. They include: 

User interface – The user interface allows publishers to interact with their SSP in a visual way. The user interface allows them to manage the SSP and view reports about its performance.

Header bidding – SSPs use header bidding in order to send ad requests to multiple ad sources and obtain bids simultaneously.

Inventory and campaign management – SSPs allow publishers to manage their inventory, which consists of their collection of available ad types and spaces. They also have the ability to stop receiving ads from certain advertisers or block specific ad types.

Analytics and reporting – SSPs assist publishers in creating and viewing reports about the performance of their ad inventory. These reports include impressions, clicks, and fill rates.


How does a supply-side platform work?

Supply-side platforms are connected to multiple ad networks and ad exchanges. They store information about available ad inventory on a publisher’s content. When visitors begin to load that publisher’s content, the SSP sends an ad request to the ad exchanges it is connected to. Occasionally, SSPs will connect directly to DSPs. The ad sources then bid on the ad space by telling the SSP how much they are willing to pay for the impression. The SSP makes a decision based on price and several other factors and serves the winning bidder’s ad on the content being loaded. Though there are many steps involved, the automation of these ad technologies allows these transactions to occur in mere seconds.


Difference between demand-side platforms and supply-side platforms

Demand-side platforms and supply-side platforms serve similar functions, but they work for organizations on opposite sides of ad transactions. An SSP is specific to a publisher who creates web or mobile content that supplies ad space for advertisers. The SSP manages how this ad space is supplied to advertisers. A demand-side platform is used by an advertiser who wishes to promote products or services, and therefore creates demand for ad space. DSPs manage the bidding and purchasing of ad space on publishers’ platforms through ad networks or through SSPs. DSPs and SSPs work together, along with other adtech such as ad networks, in order to create ad transactions which fit the needs of both sides.


Advantages of supply-side platforms

In the end, an SSP’s function is to increase ad revenue for publishers and to give them control over what advertisements they display. SSPs provide publishers with many advantages over manual ad placement, including:

Real-time bidding – SSPs allow ad exchanges and DSPs to automatically bid on open ad space in real time as soon as a visitor views a web page or mobile app. Ad space is sold to the winning bidder, which is typically the bidder with the highest bid. This saves publishers time and helps maximize their revenue.

Frequency capping – Advertisements lose effectiveness when they are shown to the same viewer many times. Working with DSPs, SSPs will keep track of how many times a single user has been shown a specific advertisement and will stop serving that ad if the user has seen it too many times.

Ad-network optimization – Ad-networks vary in their payment and their willingness to serve ads. Some networks may pay more per CPM, but not fill all of the required ad space or vice versa. An SSP will consider these requirements and choose which ad networks to sell to. 

Price floors – SSPs put publishers in control of their pricing structure by setting a minimum price for ad space bids. When the ad space isn’t filled, a publisher can fill that space with their own advertising.

Reporting – SSPs automatically track and provide reports to publishers about advertisements served on their properties. These reports include who is bidding, who is purchasing ads and how often, and how much ad space is remaining unfilled.