So, looking at the Strongcoin idea more seriously... (the ubitious requires a VPS or better with Ubuntu installed, whereas Strongcoin does not).
The fee is a modest 1% for using the Strongcoin API. I think that is more than reasonable.
Biggest issue is, it seems to wait for a certain number of confirmations before the API sends a response of "paid". I don't know about you, but if I'm a customer that wants to download goods, I don't want to have to leave a browser window open for an hour to wait for 6 confirmations to go through before I get a notice that I can download the file.
0-conf would be perfect for this sort of system. Yeah, a few people would figure out ways to scam it, etc, but those people probably wouldn't pay for the goods in question to begin with anyway, so it's kind of a moot point.
Question is, is there any way to get the Strongcoin API to reply with a 0-conf status instead of waiting for a certain number of confirmations?
I'll be contacting the folks at Strongcoin to find the answer to that question.
You don't have to use Strongcoin's API. I'd opt to use something like bitcoinmonitor.net, or bitping.net.
I like the Strongcoin API because everything is already set up for digital goods distribution. It's all already coded. I'd need to add stuff like seller logins and control panels for uploading files, etc, but the base code is all set up, which is awesome.