I recently carved out some time to correct this situation, and fell into an absolute pit of confusion when I tried to figure out what my options even were. My requirements are that my customers are global, I am UK-based, people will set up a regular subscription, and I don't have (and I think I don't want) a merchant account at this point. I'm not PCI compliant and have no intention ever to attempt that. This post is an attempt to round up some things I found out along the way.
Dwolla and Stripe
Both are currently US-specific, but I have heard good things about them both.
This looked fabulous except it's only possible to take payments from UK bank accounts. If you're selling to UK customers though, definitely check this out.
I love all things Amazon so I thought this would be a good option, even when I saw what a large percentage they take for smaller payments. Further inspection however showed that I needed a US billing address or bank account.
I couldn't find anything about recurring payments through google checkout other than some bad press from a couple of years ago saying it was flaky. If they offer this, I didn't find any plausible documentation.
This looked absolutely perfect (nice site, great interface, great docs too) but I either needed a US address or a merchant account. Would definitely revisit this in the future though if some of those variables changed because it looks like a great product for recurring payments.
These people kept on showing up in my google searches and I ended up giving them a shot mostly because they're UK based and I'm a huge believer in supporting local businesses if it makes sense to do so. A few hours later, I gave up. Their docs weren't clear, they didn't respond to either email or twitter for a few days, and I think they wanted everyone to list their products on their "store" rather than just handling my payments for me.
Which brought me to paypal. Paypal have, in my experience, proved themselves unreasonable, incompetent, untrustworthy and generally a hazard to small businesses. I'm still not sure if handling payments through paypal is better or worse than not handling payments at all, but by this point I was quite interested in seeing how it all worked so I tried to integrate against PayPal. I think it's most of the way there (if you're a bitestats customer, expect to be asked to pay for your subscription at some point) so I'll blog my actual integration at some point as well if that would be interesting.
Least Worst Option
Hopefully I just missed some excellent options along the way, there really should be payment providers who are easy to integrate with, have good documentation, and make this much easier than it seemed to me for people without prior experience. If you've got more or different experiences, would you please leave me a comment?