Notifications (outgoing): Using email gateways for SMS is unreliable and only available to a few carriers. With twitter, my users would just have to provide their twitter username. My app would then send out a DM and they would get a text message from twitter.
Incoming: A simple "d soshiku [query]" sent to 40404 and that's it. My app doesn't actually offer "true texting" since they have to send their text to an email address.
The problem is, there's a couple thousand people with their phone credentials hooked up to their accounts. I would essentially have to force them to sign up with twitter if they'd like to continue using the SMS services.
Do you think this a good idea, or a foolish one? Thanks.
Edit: My site is free, though I am working on paid plans.