I thought this was a pretty interesting graphic. Wikipedia tried a variety of campaigns to get people to donate money. Here’s the graphic put together by InformationIsBeautiful:
Out of curiosity, I decided to run some additional numbers. If Wikipedia is getting $47,433 per day with that ad, and we assume that they continued to earn that much each day indefinitely (which is questionable), then they’d earn $17.3 million per year. In contrast, the Encyclopedia Britannica earned $650 million in 1990 (their peak year). There are some other differences (like the fact that some people might’ve felt that their contribution to Wikipedia was to fix and refine articles, and the fact that Britannica had printing costs), but I also can’t help but think that it says something about the donation model.
(By the way, I also think that having a free publicly available encyclopedia for everyone is a kind of social good, so I’m not arguing that they should charge subscription fees in order to earn a lot more money. Just thinking about the donation model in general.)