I think that the problem isn't paying per se, but rather just the inconvenience. After all people already pay plenty for their web connection. Something like Flattr might be the solution.
As a flattr user from both sides (site owner and site visitor), I can't say I was entirely happy with it. Although it's well implemented.
I find it difficult that they constrained the concept to payoff = $monthly_amount/$number_of_clicks. From both sides I would prefer to be able to set and see prices, not arbitrary equal results for all the sites I click. That had kept me from clicking in most cases, because I wouldn't want to give the equal amount to go to some 1-paragraph blogpost as to a 1 hour podcast. Even though I would want to contribute for both.
Potential to integrate the amount of micropayment as a star rating - think a combined "donate & rate" action after reading / watching. Let people contribute from 0.01 to 5.00 units of currency, in easy increments, that also indicate how much they liked it. Automatically bill and aggregate monthly.
I guess the charm of their solution is that they don't have to put these complex semantics into place. It sounds like a good idea, but rating and paying are two very different things - in my example, I would merely want to reward more effort (1h podcast) with more money. That doesn't mean I didn't like the short blogpost.
Wouldn't one solution be to simply Flattr the podcast more than once? Click three times, and the podcaster will get three times the slice your blogposter will.
That's also not possible, unfortunately.
There's the option to also flattr the side-wide button, but that also kind of defies the idea of putting it where you want it to be (because that's also feedback for the publisher, obviously).
I find it difficult that they constrained the concept to payoff = $monthly_amount/$number_of_clicks. From both sides I would prefer to be able to set and see prices, not arbitrary equal results for all the sites I click. That had kept me from clicking in most cases, because I wouldn't want to give the equal amount to go to some 1-paragraph blogpost as to a 1 hour podcast. Even though I would want to contribute for both.