Update: We’ve released a new post with more information here:
Gmail SMS verification: details, reasons and stuff to try
In our office today we noticed a strange occurrence. While signing up for a new Gmail account we were told that in order to verify the account we need to give Google a mobile phone number, so that they could send us an SMS verification. Aghast we tried again.
On further attempts the message vanished. Sign up proceeded as usual.
A little more research found the following in their help section:
If you’d like to sign up for a Gmail address, you need to have a mobile phone that has text-messaging capabilities.
If you don’t have a phone, you may want to ask a friend if you can use his or her number to receive a code. Also, if you know someone who already has a Gmail address, you can ask them to email an invitation to you. One of the reasons we’re offering this new way to sign up for Gmail is to help protect our users and combat abuse. Spam and abuse protection are two things we take very seriously, and our users have been very happy with the small amount of spam they’ve received in Gmail. We take many measures to ensure that spammers have a difficult time sending their spam messages, getting these messages delivered, or even obtaining a Gmail address (spammers will often use many different addresses to send spam). Sending invitation codes to mobile phones is one way to address this, as the number of addresses created per phone number can be limited.
…
Will Google keep or use my mobile phone number?
Google will use your phone number to send an invitation code in a text message to your phone. In doing so, we store each phone number to make sure it is used to create a limited number of accounts.
Your number will also be associated with your account to avoid unnecessary future verifications for other Google services. For more information, please review the Gmail Privacy Policy: http://mail.google.com/mail/help/privacy.html. In accordance with this policy, your number will never be sold or shared for marketing purposes without your permission, nor will we contact you using this number without your express permission.
Obviously, the intent of this is to prevent mass email signups, but we can’t help but wonder if there is some deeper purpose to all this. With Google’s push into the mobile market recently—with hosts of mobile apps, phone oriented services like latitude, and of course Google Android—the integration of mobile phone numbers with Google accounts may be part of a broader integration of mobile phones and Google services.
