I emailed Virgin about a week ago to check it was not a scam and they replied:
Hi John,
Thanks for your email to Virgin Mobile about our free text message offer.
We are pleased to tell you this is not a scam but yet another one of our fantastic offers.
Soon, you'll be able to text other Virgin Mobile phones for free in the UK. It all starts from the 28th of April 2006 and it lasts until the 30th of September 2006. That's all summer long!
You can send up to 1000 texts a month to other Virgin Mobile phones in the UK. And it won't cost you a single penny, you dont even need to have credit on your phone to take advantage.
What's more, it doesn't matter how you pay – all our customers can text each other for free. So if you're on a bundle, or a Pay Monthly contract, you won't pay a single penny, or lose a single text from your monthly allowance either – every text to other Virgin Mobile phones is free in the UK.
And just to let you know, while texts to other Virgin Mobile phones are free, the rest of our costs will stay exactly the same. It'll still cost just 10p to text another network in the UK and only 30p to send a picture message anywhere in the world. The cost of texts to shortcode services and group text services will stay exactly the same too. You can check out all our costs online at virgin.com/mobile.
There are a few terms and conditions around our free text offer, too. Your free texts are for your personal use only and you won't be able to take them with you from month to month. You can check out all the legal stuff online or by talking to our team on 789, or get more information buy calling 22524 for free.
If there's anything else we can help you with, just reply to this email. You can also give us a call on 789 from your Virgin Mobile phone – it's just 10p, no matter how long you talk for. Or, you can call us on 0845 6000 789 from a fixed line phone. These calls are charged at local rate.