There are several products like Chargify, but now Google checkout is about to start recurring payments and subscription billing. It is currently in Beta, but I am integrating it into one of my sites, and it seems nice. Google is well trusted by people, so it may be better than a company like Chargify that most people probably haven't hear of. it also allows for item purchases at the same time as a subscription. So a customer can order Widget 1, and a 1 year support subscription for Widget 1.
My only hesitation with going to Google with this is how notoriously difficult it can be to reach a real support person if you have a problem. There are all sorts of horror stories on the internet of people who had their accounts frozen or other issues and were unable to find any way to contact a human being. I dare you to try and find a contact phone number for support, unless its changed recently you won't be able to. IMO this isn't acceptable for someone who's handling my hard-earned money. If I have a problem I should be able to call them up and talk to a support person about it.
Not to hijack the thread but I also ran across <a href="http://www.opengateway.net/" rel="nofollow">http://www.opengateway.net/</a> , an installable (as opposed to SaaS) recurring billing solution. Was wondering if anyone had tried it or had feedback.
Google is definitely a trusted source, however, they're a monster in size and that sometimes leads to the inability to contact them should something come up.<p>I had a pretty severe Gmail problem once and I remember trying to contact someone or report the issue, a nearly impossible task. All I found were static help documents. Of course, that was ~4 years ago. And their support for Google Checkout may be handled entirely different from that of Gmail, but it's still something to consider.<p>Then again, I got burned by the Chargify pricing hike recently, so I can't really advocate to go with the smaller "Chargify-ish" companies, either.
You could also try PayPal's website payments standard which offers similar recurring payment functionality and identical transaction pricing. Customer's aren't required to have a PayPal account to purchase through it either.<p>Both of these services only offer checkout capabilities. They don't offer product/subscription management or other advanced features like dunning which gateway wrapper services like Chargify, Recurly, Spreedly and ChettarGetter offer.
If you want to not worry, can spend a week cooking it up and testing it, using a service like braintree (or the like, I have enjoyed only braintree), is the only way to go.