I've been working on a project for a client that involves online subscriptions. The client wanted to use PayPal's Website Payments Pro as their payment gateway. I downloaded the SDK for ColdFusion/Java and successfully installed the sample code on the server. This was quite a challenge in itself trying to figure out how to implement the security certificates, configure class paths, etc... Anyhow, after several hours of digging through documentation I found on a forum (unrelated to PayPal) that Pro doesn't support recurring subscriptions. Now, if PayPal would have simply stated somewhere within the FAQs, product comparisons, documentation, really, anywhere... they would have saved me (and I'm sure many others) massive amounts of frustration. After failing to convince the client to upgrade to PayFlow Pro, they accepted the PayPal subscription button as a substitution. Ultimately, it's going to appear slightly less professional (users will be redirected to PayPal for actual payment), but it will meet their needs.