Are you a few hundred points short of your next Xbox Live Arcade purchase? Clock up an hour on Youtube, and those missing points will be yours. Under the Triple Play promotion, Microsoft's giving away 300 MP to those who're prepared to do stuff they'd probably do anyway on Xbox Live. It's a hard life.
The promotion's split between the Gaming, Entertainment and Social categories - you'll need to complete one activity from each to get your points (thanks lgladdy). Sadly, you can't tackle several activities per category for multiple returns. Here's the list.
Play a Kinect game for two hours
Play online via Xbox Live for 10 hours
Spend 800 Points or more on game-related items (Games on Demand, DLC, XBLA, etc.)
Spend 400 Points or more on any film or TV content
Use one of the following apps for 10 hours: BBC iPlayer, blinkbox, Crackle, Last.FM, LOVEFiLM, MUZU, Netflix, Sky, VEVO or Zune
Use Facebook on Xbox Live for one hour
Use YouTube on Xbox Live for one hour
Use Video Kinect on Xbox Live for one hour
There are precisely two hours left in my (official) working day, and I've got Kinect set up on the floor near this computer. I reckon I can probably earn my 300 points just by tapping my foot.
Go on, do yourself a favour. The offer runs during April and April only.