Meh, I`m probably late to the party already, but just a few things.
Running a community (site) is a tough and thankless job (I`ve learnt of that times ago), but if you really want it to flourish, you`ll need to put some dedication into it, which usually involves spending cash on it without expecting anything (monetary) in return. Those who do will usually end up with the best communities, but I fear that not everyone`s got the financial capabilities to pull this one off, but just some food for thought.
Once you do try to actually make profit off your community site, your community members cease to be your guests, customers, or w/e, they`ve become your cash-cowing cattle. That`s not what you really want them to become. (And that`s why I consider sites like Curse the cancer of, well communities.)
And I would /never/ bow down to anything Google (or Facebook, Amazon, and, well you get it) tries to dictate you to do. These cancerous companies`ve already got far more power on the internet than they`d ever deserve, and they definitely shouldn`t be able to dictate what we`re allowed to do, and what not. Plus, from what I`ve been told by some site owners who did, their advertisement revenue wasn`t that significant, either, but I have no real idea bout this, so take this with a grain of salt.