Do you really think it's a good idea to put ISPs in the position of doling out micropayment money? They would need to collect a fee for processing it, and what business rules are in place for transactions smaller than the fee?

And similarly, how do you prevent fraud? WAP was a walled garden experience; if I can send money to any site on the Internet by clicking a button, what's to stop a malware author from using their malware to send lots of clicks (and thus money) to a site they run?

Technically, micropayments aren't a difficult problem to implement. The business rules around financial transactions (which exist for good reasons) often present an intractable conflict with what would be a viable user experience.

> if I can send money to any site on the Internet by clicking a button, what's to stop a malware author from using their malware to send lots of clicks (and thus money) to a site they run?

Already happening with pay-pr-click ads etc.

Yeah, but with PPC ads everyone knows it happens and doesn't care. Ad fraud in general is a bad analog; when an advertiser buys an ad, they're looking for a certain response from a campaign. If they get the response for the dollar amount they paid, they don't care what the CPM is (and all removing the fraud would do is raise the CPM).

Micropayments would be a different story since the money would be coming out of individuals' pockets.