> Anyway, at $10/mo I can't quite put my money where my mouth is. $5/mo would be much more attractive, and I would guess they'd have better profit at that price. How much does each user cost them?

Not really. Between free and paid users, TFA says they average roughly 27 searches per user per day; 1000 searches costs them $12.50. If each user (TFA says roughly 10% of searches come from the free tier) is averaging 810 searches in a month, that puts their bare cost at close to $10.13 per user per month, not including salaries and other operating costs.

I'm one of roughly 2.6k paid users at the moment; they estimate the need for 25k users to be sustainable. There's so much about google and most of its current alternatives that legitimately disgusts me- voting with my wallet is the only option I really have.