This week’s headlines: Amazon Launches #AmazonCart, Facebook Announces

Video Metrics, Twitter Shares Slide as Lockup Ends, Twitter Introduces

Language Targeting for Ad Products and Tumblr Launches Mobile Customization

Features.

The week’s news quick hits: John McAfee Releases Secure Messaging App,

LinkedIn Introduces Different Ads for Language Preferences, Twitter Makes

Deal with Exclusive South Africa Ad Partner, App.net Reports Revenue

Viability, LinkedIn Announces CardMunch Shutdown and Twitter Expands

One-Click Video Ads to More Advertisers.