Rather than micropayments, I think there's a need for micro-tipping. I may not want to make the mental effort to decide whether to pay 4 cents for an article before I read it, but I often feel grateful to the author of a piece after I read it. The problem is that there is no convenient way to act on that impulse -- no way to make a quick micro tip. An upvote on Hacker News and Reddit serves this purpose, but there is no money involved and the upvote link lives on the aggregator's site instead of the content provider's site.