Nickflame is correct. They're registered as a tax-deductible non profit org. Check the Wikimedia Foundation, Inc.'s website. The donation links are there.
well yes, due to it saying "Your continued donations keep Wikipedia running!" on every page. With a link to 5 different ways to donate.
I have seen donation drives on Wikipedia. I can't say when they do it but they definitely have times when they ask for donations and set goals.
You guys are sort of right. Wikipedia is a non-profit. But that doesn't mean it always will be, or that it's not used to leverage a for profit venture. They are grabbing marketshare. Wikipedia is worth a ton, they have started wikia to monetize now.
So far the model of donations works well, but the only downside is that the founder's net worth is limited because it is a non profit. Wales is only worth about 1 million which isn't much considering how important wikipedia is.
Wikipedia says they are going to never sell - and that their aim to to run forever that way. Read their "about."
There is a differnce between the main wiki establishements and other small timers who use wiki technology. These small timers have ads on their sites.