As a little-l libertarian, I'd accept that there's a bit of market failure here as the friction of making payments has exceeded the relative ease of "just slap some ads on it". However I suspect this problem is fixing itself over time. Ad inventory is only going to increase, which drops what you can change on average, which is slowly but surely going to take "just slap ads on it" out of the reach of more and more people, and alternate payment methods, while not quite as easy as just shouting "Micropayments!" and walking away with a smug expression, are in fact developing. Kickstarter is one example, and other models like that will develop and return the concept of "patronage" to the field of culture by mixing in a heavy dose of "crowdsourcing". And once we're comfortable with that, who knows what else we might come up with?

And hey, maybe somebody will figure out that whole micropayment thing too. But at least now there are increasingly concrete demonstrations that they were never the only solution, which is fortunate since they don't seem to work.

I'm actually more optimistic now that we can escape from ads as the only choice than I've ever been before. I'm hoping that this is the last year or two that cstross could make this post and have it still seem a reasonable concern.