logistically that's unworkable for a number of reasons (bitcoin fees make micro payments...less useful; PAM is...not ideal; etc.) but a fine thought nonetheless.
You could have it accumulate a wallet and send over when it reaches sufficient magnitude. Or have it tally the number of times it would have done it, and then ping you when you've used it a sufficient amount, for whatever definition that is for you. Think Sublime Text save dialogs for the non-paid version.
It could just count the number of logins and do a transaction at the end of the day|week|month