An interesting point, but the way most program works is that there's a
minimum needed before the send a check, but it accumalates as long as
is necessary. So, eventually, some years from now, perhaps, we'd get
a check.
I do think you raise a very important point, though -- the amount of
money that the Wikimedia Foundation would make from such programs is
not likely to be huge, anyway.
By way of comparison, I conservatively estimate that if we put paid
listings from Overture or Google into the search results page, we
would make $1000-$2000 a month. I'd be very opposed to doing that.
--Jimbo