I'm sure they have no idea how much stock he has or what the valuation is.... Like any other start up, the stock isn't convertable or worth anything except "on paper". Wales is on the board but doesn't actually work there.

(disclaimer: I do work there. :)

Wikipedia doesn't have ads.

I'm not talking about Wikipedia, I'm talking about Wikia ;)

Wikia.com is a network of wikis that he founded. A really popular network that hosts the official Star Trek wiki among thousands of others.