I really like the idea of having a pledge bank and
keeping people who are
making regular, albeit small, donations informed about what WMF is up to. If
we can say, "Your donations allowed us to run a number of workshops in South
Africa. That was 3 months ago, the Africaans Wikipedia has grown by x
hundred articles since then." My objective here? You're showing donors that
their money is making a difference, even if - with English WP at 2 mill+
articles - they never notice the difference.
The problem is, most of the money goes on just keeping the servers
running, it doesn't go on anything interesting.