Around one in five Web users now send a do-not-track request when they surf the Internet, according to Interactive Advertising Bureau general counsel Mike Zaneis. He adds that the IAB expects that proportion to increase to 50%.

Yahoo’s spending spree continued unabated Wednesday with the acquisition of San Francisco-based Xobni, which could it help to further enhance Yahoo Mail. The company’s Smartr product line indexes a person’s emails from all their accounts and creates a unified address book with a profile of each contact. The profiles can include a photo, job title and email history along with a contact’s post on social networks like LinkedIn, Facebook and Twitter. Smartr apps or plugins are available for Android, Gmail, and iOS. Xobni also provides contact management tools for Outlook and BlackBerry. Yahoo didn’t disclose terms of …

In its latest mobile deal, Yahoo on Wednesday announced acquiring Qwiki, the startup behind the iPhone app that automatically turns a user’s pictures, music and videos into slideshow videos. Terms of the transaction were not disclosed, but AllThingsD estimated the purchase price at $40 million to $50 million. The tech blog first reported on the rumored deal a few weeks ago. Yahoo said in a blog post it will continue to support the Qwiki app and the company’s employees would join its New York City office “to reimagine Yahoo’s storytelling experience.” Qwiki launched its iPhone app earlier this year …

General Motors' Chevrolet unit is launching a marketing campaign for the new Silverado pickup truck. The campaign, "Strong". The effort features a song by Grammy-nominated country artist Will Hope. The effort launches July 4.

Zynga CEO Mark Pincus on Monday confirmed he’s stepping down in the wake of a widespread company layoffs and disappointing game sales. Taking over as Zynga chief executive is Don Mattrick, former head of Microsoft Xbox and gaming division. “I’ve always said to Bing and our Board that if I could find someone who could do a better job as our CEO I’d do all I could to recruit and bring that person in. I’m confident that Don is that leader,” stated Pincus in a blog post …

Patrick Mork, global marketing director for Google Play, will soon leave the company after a two-year stint, according an AllThingsD report. Prior to joining Google Android unit in 2011, Mork led marketing efforts for independent app store GetJar. He has previously also served as EMEA marketing chief for game developer Glu Mobile. His next move is not clear.