With more than 300 million downloads and 50 million active monthly users, AdBlock Plus is among the top tools web surfers use to block intrusive or otherwise annoying online advertising.

It’s been around for ages and we’ve known for some time that the service maintains a whitelist that lets small blogs and websites get a free pass while certain advertisers can squeak by for a nominal fee. The paid whitelisting is, after all, how the company generates revenue to sustain its existence.

A new report from the Financial Times ousts a handful of paying advertisers and the names likely won’t surprise you.

Those that pay to join the whitelist are said to include Amazon, Google, Microsoft and Taboola. The deals are confidential but according to one source that didn’t want to be named, Eyeo – the German-based company that makes AdBlock Plus – commands a fee equivalent to 30 percent of ad revenues that a company would make from otherwise blocked ads.

Amazon and Google declined to comment on the matter while Microsoft provided a canned response that hardly addresses the matter.

It’s worth pointing out that AdBlock Plus’ use of the whitelist is optional although highly recommended. By allowing some ads to get through, users get to support sites that reply on advertising but do so in a non-intrusive way.