Microsoft and Sky are offering free Microsoft Points as an incentive to get more people to sign up for the latter's Now TV streaming video service.
If you sign up for a free 30-day trial through Now TV's special Xbox site, you'll get 800 Microsoft Points added to your Xbox Live account.
If you then decide to continue after those 30 days and pay £8.99 for another month's access, you'll be credited with another 1600 Points for a total of 2400 Points.
For those unfamiliar with it, Now TV is Sky's equivalent to Lovefilm and Netflix, offering streaming movies on demand through various Xbox 360, PC and iOS apps. While it's more expensive than its competitors (£8.99 for the first three months then £15 a month afterwards), that premium cost does mean many of its films are more recent, roughly in line with the Sky Movies selection.
You need to be a new Now TV member to take advantage of the offer, so if you've already tried it out you're out of luck. You can find all the details on Now TV's Xbox site - if nothing else it's worth doing the free trial to get your free 800 Points, as long as you remember to cancel before the 30 days run out. You'll need to watch at least 90 minutes' worth of video during that 30 days for it to count.