Yes, Fluther gets paid a (very) small amount each time Fluther displays an advertisement. We also get paid a small amount each time somebody clicks on an ad. Advertisements are only seen by visitors who are not logged in.
Theoretically, we could boost revenue by displaying ads to members, but I’m not sure if our users would like that.
We could also make the whole “ads-and-membership” issue into an opt-in program. Users could voluntarily see the ads as a way to earn money. Given how little money each individual ad earns, this idea isn’t worth it. Just to give you a good perspective, website advertising profits are often measured in the range of “cents per thousand views.” Google policy also says “I will not click on my ads nor encourage others to do so.”
Of course, we could simply increase the number of ads displayed to nonmembers. We already display 2 ads per page, and I don’t want to simply make this place look any uglier.