Microsoft has been quite active in offering extras along with a Windows Phone purchase from the start. Verizon users get a free Xbox console game and some other countries even offered a free Xbox 360 console with a Windows Phone purchase. When I originally bought my device at launch, I was able to download the Xbox LIVE game ilo milo, which at the time was exclusive to At&t users.
This current offer for At&t users has been around for a while, but for new users who may not be aware, Microsoft and At&t are teaming up to give new phone buyers 3 free months of Zune Pass. Zune Pass is a music subscription service which give users access to download or stream the entire music collection on their WIndows Phone, PC, Zune device or Xbox console. Normal Zune Pass subscriptions allow the user to keep 10 songs each month, so if you purchase music regularly, Zune Pass is a no-brainer. It’s simply the best deal in music and one that Microsoft would be well-served to promote very often.
Follow this link for more information on the offer for At&t users.