Thanks for the feedback though. Admittedly, we could have put more time into the landing page.
I've had mobiles in some 15+ countries and that's the first I've heard of being charged for inbound texts. Definitely a rip!
A path we're considering that might have some more obvious use cases: a mapping of phone numbers -> mailing addresses. That way in your mobile postcard app, you can choose a friend to mail a card to, even if you don't have their mailing address in your phone. The first-time recipient would automatically get a text message along the lines of: "Steve would like to send you something. What is your mailing address?"
If i receive an SMS that says "Steve would like to send you something. What is your email address?" I might reply because I am happy for Steve to email me things.
However that does not necessarily mean that I want to allow anyone other than Steve to email me from that point forward... would be a nasty surprise if you dont explain this clearly.
I'm guessing.
Full disclosure: I know / am good friends with the original post author / creator of ThinBox, but that had no influence on my comment.
But really, why email their number when you can just message them for their email (or using gvoice or something similar)?
Also note: Thinbox only works with U.S. phone number at this time.
Interested to see how it develops!