Social Media News: LinkedIn introduces new SlideShare products for mobile & Twitter adds new way to promote mobile apps
Social Media News: Pinterest adds Pin It buttons to more platforms, Facebook enlarges sidebar advertisements, & Facebook tests clearer prompts for privacy settings
Social Media News: Vine adds messaging, Pinterest a new way to track pins, & Twitter now supports multiple photos per tweet.
Social Media News: Facebook Lookalike Audiences, positive effects of Twitter advertising, & DianDian Interactive social gaming success
Social Media News: Twitter broadens TV conversation targeting, Pinterest gives optimization tips, &Facebook beta-testing Unread Stories