According to their own numbers, wikipedia has around 22 million articles in 270 languages, along with some 850 000 media files (
source). To say that they're orders of magnitude bigger than TFP still doesn't quite do the size of the gap justice. I'm not the slightest bit surprised that their costs run into the millions -- it's thoroughly impressive that they manage to keep everything running quick and snappy throughout it all.
I suspect a large proportion of their funding comes from various grants. The kind of funding we're talking here just doesn't come from donation drives.
And yes, it's stupid easy tot get lost. Welcome to the internet. Enjoy your stay.
(Try tvtropes some time).