Turn your greeting cards into a book!

I came across this on Pinterest. I can't find the original link (seems to be uploaded by a user via an iPhone) but it's really worth sharing. I started one for each of my children tonight and I plan on making one for myself. It's such a sweet idea. One day I'd love to bind them into some kind of book you can keep adding to (instead of a binder) but with that being said, there's nothing wrong with a binder, right?

If you happen to come across the original source, please let me know so I can reference it!