It does require spending all your votes every day, mind you. And originally I was going to say 10 on average, but that seemed a bit low. Since I have no precise idea of the amount, 15 sounded like a decent guess - but still a guess. Still, it works for the point I wanted to make: it is a mild encouragement, but an order of magnitude lower than what you get for posts, and thus not abusable.
Makeshifts last the longest.