Philip K. Dick's Ubik is a masterful
exploration of virtual realities.
This is about communities that exist on the internet.
As in real life, there are two types: real and virtual.
In real virtual communities, you are you, though you might use a nickname and avatar. You talk to other real people, and while there might be a theme to the discussion, there is little or no transaction, such as exchange of points or ratings. Creation of bogus characters is thwarted.
In virtual virtual communities, you are represented by a proxy. It can be a comic book, or an ad, or a dragon. The balance tips so that the false image dominates, and interactions are based on the false images. In fact, "false" might be the wrong word. The image is you.
Gamers have been acquainted with role-playing for years. But now there are sites where you can "be" your blog, or your comic, and try to bring real life improvements to it. One example is EntreCard.
Will we ever "be" advertisements? Will I select my favorite banner ad for my comic and interact somehow with others doing the same? That would seem to be a virtual, virtual, virtual community, in which an avatar of an avatar of you is participating, so perhaps it's a far-fetched notion. Ads are sure to get smarter, but not sentient.