My main concern would be spam. At the moment I get telemarketing calls on my mobile, but with this people could spam me through my phone number. You might want to mention to people how you combat that when you send your opt in SMS

If I have their phone number why can't I just call/txt them and ask for their email address?

Bob is sending bulk email to a list of contacts, some of them are email addresses and some of them are phone numbers. Calling texting each phone number to get an email address is an extra step that Bob doesn't want to take.

I'm guessing.

How on earth do you get people's email addresses? My initial instinct is that your are just farming phone numbers...

If they aren't registered, we send them a text message asking for them to reply with their phone number. Any e-mails thereafter to [YOUR_NUMBER]@thinbox.com are automatically forwarded.

Thanks for the feedback though. Admittedly, we could have put more time into the landing page.

Make sure you make it easy to cancel, e.g. instructions in the first text for how to block your number from the registry. People who do not have a texting plan in favor of iMessage, Skype, etc. but do not block all incoming texts by default will thank you. I got a text like this recently from AIM mobile-something-or other from some weird spammy address. The second message contained instructions on how to block any future requests, but afaik I'm going to see all the messages that were sent in the meantime on my bill at $.10/ea– I'm glad I wasn't roaming, since the price essentially triples.

The STOP command is mandated. I hope these guys get someone that actually knows how SMS works from the legal side.

How is it different than me just texting them directly asking for their email? I suspect they'd be more likely to send their email to me than to some random company trying to act as a middleman.

The idea is that it can happen automatically and seamlessly. We are planning to release a mobile sync app that will automatically "fill in the blanks" in your contact list. Basically, for any contact that has a mobile number and no email address, we'll populate the field with [Number]@thinbox.com

"fill in the blanks" makes your own service partly redundant doesn't it? And how many of my contacts will be using it?

borplk, the idea is that all of your contacts are contactable through the action of e-mailing them via their thinbox address. Even if they aren't registered, they will still be contacted (via SMS asking them to register) by the unified action of e-mailing them.

'Registered'? With whom? I didn't register with anyone as far as I know, yet I received an email (on one of my 5 email addresses).

This looks like a very nice database to sell to 3rd parties.

Ultimately, our plan for Thinbox is that the number mapping will be connected to more information than just an e-mail address.

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?"

This raises some questions for me. I can't try it out, since I am not in the US, but what is the exact explanation you give in that initial text?

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.

You do know that this has been standard functionality on all the US carriers for years anyway, right? There is absolutely nothing useful about this service. One quick Google search can get you the specific domain to email to for any carrier. They all follow the same format, [number]@carrier.com. This service is about 5 years behind the times. I've been emailing to SMS since before the iPhone.

For sending text messages that is correct. It may not be clear enough that the purpose of e-mailing a [NUMBER]@thinbox.com address is not to send an SMS to someone's phone. The initial SMS is just a way to ASK for the recipient's e-mail address and create a mapping that works for future e-mails. So essentially it just couples two separate types of "addresses" for a person into a single address.

Also, after your number is coupled with an e-mail address, you will not receive any more SMS messages. E-mails sent to [NUMBER]@thinbox.com will automatically be sent to the e-mail address provided

My biggest concern is seeing an "email" where my text messages. I get text messages all the time, and they're usually pretty high on my list of important messages because I know that 100% of my text messages are definitely not spam and that i should at least read them. Using email to send me a text only makes me think i got spam and i'll just delete the message, i probably won't even read it.

But really, why email their number when you can just message them for their email (or using gvoice or something similar)?

Can you explain why someone would want this? I'm not sure I've ever been in this situation before (only have someone's phone number but want to email them).

I think they may be on to something here. It simply means you can have one source (contact detail) to reach out into many. It may not even be a pertinent MVP for every individual, but the linkage, and potential with a bit of creative thought behind it, is pretty cool.

Full disclosure: I know / am good friends with the original post author / creator of ThinBox, but that had no influence on my comment.

So, does this actually do anything? I've tried twice and not seen anything on the phone end . . . .

Blocked the email-to-SMS gateway at your carrier? I did that years ago since I don't pay for unlimited SMS (which I consider a massive scam) and don't want to get dinged because I get charged for inbound (also a massive scam, thanks US carriers).

You get charged for inbound?

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!

Yes - all major US carries do this as far as I know. AT&T and Verizon for sure (unless you pay $30/month for unlimited SMS)

It only works with U.S. mobile phone numbers right now, sorry!

Umm, I'm in the U.S. Texas to be specific with a U.S. Phone number.

Just sent an email to the connect email address with more details.

I really appreciate any feedback. This is an early stage version, but I wanted to get it out there and see what people had to say before taking it too far in one direction.

Also note: Thinbox only works with U.S. phone number at this time.

Interesting approach to cross service contact. We've taken a different tact with our app - http://tray.io.

Interested to see how it develops!