I haven't implemented Chargify on my site yet, but I did sign up for the beta and have looked it over. Plus, I've been running subscriptions via Amazon FPS for about 2.5 years now.
By far, the #1 thing I like with Chargify is the ability to modify existing subscriptions. With Amazon (and PayPal too, I believe), once a user signs up with a rate and term, it's locked in. To change the rate they'd need to go through the workflow again. So, if you say $5/mo and want to move to $10/mo, you're screwed. Good luck getting them to go through the checkout again.
Not that this is something you'd want to do all the time, but perhaps you've been doing something for a couple years and want to raise your prices a little. Or, you want to add another tier of service and automatically bump some customers into it. It's easy with Chargify, and very hard with the others.
There's other stuff too, but it's hard to articulate. Believe me, having been there, I would highly suggest that anyone seriously evaluate Chargify over PayPal or Amazon SimplePay. Definitely DO NOT roll your own, like I chose to originally. It will be an unending source of pain.
- What are the fees I have to pay?
- What are the features I get?
I'm thinking of trying an idea of a paid service for a first time and just trying to figure it out.