Unsolicited "your activation code is..." SMS

[Ext User(googlegroups@sensation.net.au)]

I received two SMSs in a row saying "Your activation code is: <number>"

The first was from +61429700000 (0429 700 000)
The second was from "Activation" (the actual word, not a phone number)

I'm sure I'd seen a thread about this recently but a search didn't turn
up anything. Has anyone else been sent these? I'm wondering if it's
some sort of scam to subscribe people to premium content when they
reply with the activation code. "Hey, you sent the activation code, you
must have agreed to the T&C..."

[Ext User(Mike)]

googlegroups@sensation.net.au wrote:
> I received two SMSs in a row saying "Your activation code is: <number>"
>
> The first was from +61429700000 (0429 700 000)

Not a "premium" gateway. Might just be a wrong number.
Someone types the phone number into a website, and it sends the
code by sms. The person is then supposed to type the code
on the website to prove the mobile number is theirs.