Thanks a lot for your POSITIVE feedback! :-)
And, of course, I agree with regards to the landing page - it'll be ready by Monday next week. It takes some time to prepare nice image that (we hope) will help to explain the purpose of the website.
15 karma · joined September 16, 2008
The reason we decided to use FB only auth is that we felt that in order to provide the same feature set with FB and without it would require quite a lot of duplication on our site. And the more social features we add - the more duplication it requires.
For example, for a plan you can specify "friends only" visibility - and for this to work we need to support friends lists in our app. We also use FB to send SMS reminders (if allowed by a user) - and that's not the easiest and cheapest thing to implement from scratch.