Bloomberg is reporting that YouTube has seen its mobile ad sales triple in the past six months, which is partly due to increased usage of its ad-enabled YouTube apps on both iOS and Android. The company has seen a 42 percent increase in app usage from a year ago, with 70 million smartphone owners using the app in March the United States.The recent growth in usage follows Apple Inc.'s decision last year to drop YouTube as a core application in the iOS software for iPhones and iPads, said Phil Farhi, director of product management at YouTubeSix months ago Google launched a native YouTube app months af
