Clay Shirky wrote about micropayments and free content a while back: http://shirky.com/writings/fame_vs_fortune.html

Basically, he's saying that micropayments will not work because they introduce a transaction cost into the act of reading: you not only have to decide if you want to read (or skim) the article in question, you have to decide if it's worth x cents as well.

And that transaction cost kills the transaction before it happens, never mind the x cents that would have been transferred.