Why would I use this? (Not saying I wouldn't, just want to know why you built it and why I should use it instead of an existing service.)

The benefit of Bitly is that users recognize the link. It doesn't make them feel like they're about to get a virus.

Furthermore, Bitly has lots of nice features and actively fights malicious links. So the truth is, users actually can trust Bitly links a bit more than a service that just started up.