I have only the lamest colloquial proof, but I don't think the community ads are coming up. I haven't seen them. When I asked in chat, nobody else had seem them. The stats page doesn't indicate how many impressions the ads have been given, only click-throughs (which is a flat 0 if you disregard me testings the link). Do we know that they're working, or do they come up that infrequently?