James Stanley

SMS Privacy month 1 review

Mon 10 October 2016
Tagged: smsprivacy

It's a month since I launched SMS Privacy, a web service offering anonymous phone numbers paid in Bitcoin. This is what's happened over the last month...

172 users signed up, paying a total of 0.52 BTC (~£260).

At launch the site only supported SMS and only provided "virtual" numbers. A major use case for an anonymous phone number is to receive signup verification codes, and unfortunately the API provider blocks such messages. So shortly after launch, I added voicemail support, which allows it to work for services that can read the number as a voice call.

For services that do not provide the verification code over a voice call, I now offer "premium" or "physical" numbers (the A/B test to decide on a name is still inconclusive). The premium/physical service is where I have real SIM cards in real phones, running an Android app that forwards all the received SMS to the SMS Privacy server. It's like my own mini-Twilio service, but with no message filtering.

When a phone needs a new number (i.e. the user it was assigned to stopped paying for it) it vibrates every 5 minutes, and when I notice it vibrating I put a new SIM card in it. The phone then announces its number to the SMS Privacy server and the new number is made available for sale. So far there is only one phone, but I've got another on its way and I plan to add more until I can meet the demand.

I added an A/B testing framework shortly after launching, and one of the most surprising outcomes was that replacing the picture of a spy (?) with a picture of Kim Jong-Un increased signups by 50% (statistically significant, p < 0.05). I have no explanation for that. I only chose the picture of Kim Jong-Un because it was a convenient black-and-white clipart to experiment with.

A few users have emailed to request alternative payment methods, but none of them have suggested the same alternative, so it's unlikely I'll be adding any soon.

My biggest difficulty (as ever) is marketing. I now have a good service that can take users in and get profit out, I just need a way to get more users in, and then I can apply that repeatedly to get more profit out. This is something I plan to improve over the next few months.

If you like my blog, please consider subscribing to the RSS feed or the mailing list: