[sounddust]

Regardless of what you are referring to, you are still using this number as if it were unique visitors. You say "multiply your total audience size by .00124" (total audience size is number of unique visitors). Then you say "That comes to about 8 million people" (people are unique visitors). You're still doing your math based on the assumption that 5 billion unique people visit Wikipedia each year.

Your math as it stands is impossible, and you're still using it to support your argument. Even if you assumed every internet user in the world uses Wikipedia, that means that the average donation per user would be 0.003875, more than 3 times your estimate. With more reasonable math (and taking into account that Wikipedia does not fundraise 24/7 and is not aggressive) you can see that the average visitor is likely to donate an order of magnitude more than you're claiming.