Here's what you may have missed this week in the world of social media, tech, and other fun stuff:

• Facebook Adds Craigslist-like Features for Buying and Selling - As an alternative to services like Craigslist or eBay, Facebook users sometimes turn to Facebook Groups to make purchases. Previously, however, this was mostly done informally.
• Amazon Will Let Bloggers and Brands Host Their Own Giveaways - Amazon is pushing the idea of using its platform as a sales and promotion channel with a new self-service tool called Amazon Giveaway that lets individuals and brands host their own giveaway promotions.
• Apple's New Ad was Filmed Entirely on an iPad - Apple released a new iPad ad during the Grammys on Sunday, showing how the tablet can be used to create music. The 60-second spot features recording artists Elliphant, Riton and The Gaslamp Killer, showing various stages of the creative process. In the ad, we see the iPad being used to write and read lyrics, create beats, record and mix tracks — and, finally, perform live. It was filmed entirely on an iPad and based on current rates for ads during the Grammys, Apple paid more than $2 million for the spot.
• You Can Now Decide Who Will Run Your Facebook After You Die - When a Facebook user dies, their page often becomes a memorial, frozen in time. Now, members can designate someone to manage their account posthumously, Facebook said this week.