Wikipedia Founder gives away the ultimate social networking site?

This is just a quick mention of this story (also here) . Jimmy Wales tells us he plans to use to offer us all free hosting plus 100% of all advert revenue from the stuff we write, as long as we keep a link to his company Wikia. He plans to host all sorts of open source software (including wordpress which creates this blog) and allow us all to create multiple author blogs with voting and feedback buttons etc etc.

How will he make his money – it looks like it should come from advertising on wikia.

This is an enormous opportunity to draw many more people into using the social web, and for non-profits to not only see their web cost tumble, but start earning money from the things they and their supporters are saying. It is also likely to become the focus of a huge amount of (mainly open source ?) creative effort to make the different websites work well and look fab.

Still don’t understand it properly though.