Ask HN: "Pay with a Flattr", what do you think?

What do you think about the idea of "Pay with a Flattr" service for webapps? I have tried both www.paywithatweet.com and flattr.com on some of my webapps, and like both ideas. Now I think that Flattr.com should launch a service where users of webapps will pay using Flattr. This would mean forcing users to pay using Flattr to get access to the webapp. Would this work?