Supply Side Platforms, or SSPs, are tough to distinguish these days. With so many names in the market its becoming increasingly difficult to understand each companies value proposition and just what sits behind their exchange.

One thing is common though. In order to be considered an SSP you must have publishers participating in your exchange.

In order to better understand how they stack against each other we used a simple table compiled by a company called AdAuth, who specializes in Ads.txt reporting.

The below table ranks the top SSPs by the number of publisher that include them in their ads.txt file and measures market share.

It’s an easy and level playing field to determine who has the largest reach across the industry.

ExchangePublishersMarket ShareDirectReseller
Google899,36786%4,387,5287,414,269
Xandr440,53442%1,129,3318,111,979
PubMatic418,81440%1,063,9707,162,535
Rubicon Project394,65638%1,086,6114,789,260
OpenX388,96637%969,9645,973,480
Index Exchange377,80336%781,0162,903,995
Verizon377,46236%749,7153,193,183
Freewheel362,79935%10,849,50814,007,418
Pulsepoint355,18034%319,1533,097,480

The above data was taken as of July 2020. To understand Ads.txt in more depth and search other exchanges we recommend checking out AdAuths full analysis.