Exoclick is one of the biggest ad networks in the world. Literally it is the 4th largest traffic source after Google, Facebook and Twitter serving over 7 billion daily impressions. And it is for sure the largest adult network.
They are working both for webmasters and advertisers, If you are an adult webmaster you can sell the traffic to Exoclick based on actual rates, whether you are webmaster or advertiser you can register following this link.
I highly recommend to test this traffic source to get the basic understanding of traffic optimization.