Also alleviates security concerns and PCI compliance issues if you're never storing payment info!

You get what you pay for. IMO after building many subscription systems talking directly to merchant providers or gateways (PayFlowPro, Braintree, etc), 4% is well worth not having to deal with this and just letting someone else handle all the crap that comes with subscription services.

If they do a good job of course.

I think the point of this post is that it should be as easy dropping some code into your website to enable subscription payments.

So, how did you do all this in 4 hours?:

1) Accept secure recurring transactions.

2) Get PCI compliant

3) Monitor for credit cards that are expiring and contact the users.

4) Allow a way for the user to update their payment information themselves.

5) Administer users and cancel or suspend their accounts based on their payment status.

6) Email users a couple days before each charge so they know that it's coming and what it's for so you don't end up getting charge backs and charge back fees.

7) Make it possible to upgrade or downgrade an account and plan and change the amount billed automatically.

8) Adjust sales tax per location if needed, like in some states that have a different tax per county.

I'm sure there's more. And I don't even know if this company getsubscribify.com handles all these situations that would be available in the perfect subscription system.

You could—but when you have no idea how your service will be received and you want to get from nothing to minimum viable product asap, a service like this is great. It's precisely what I've been looking for, low overhead.