Subscription sites that need some extra proof-of-work for their free trial so it doesn't cannibalize subscriptions could charge bitcoins for the trial.

I am not Dorian Nakamoto.

Some places where generation will gravitate to: 1) places where it's cheapest or free 2) people who want to help for idealogical reasons 3) people who want to get some coins without the inconvenience of doing a transaction to buy them There are legitimate places where it's free. Generation is basically free anywhere that has electric heat, since your computer's heat is offsetting your baseboard electric heating. Many small flats have electric heat out of convenience.

Bitcoin isn't currently practical for very small micropayments. Not for things like pay per search or per page view without an aggregating mechanism, not things needing to pay less than 0.01. The dust spam limit is a first try at intentionally trying to prevent overly small micropayments like that. Bitcoin is practical for smaller transactions than are practical with existing payment methods. Small enough to include what you might call the top of the micropayment range. But it doesn't claim to be practical for arbitrarily small micropayments.