Business Insider writes, While everyone else flails around and tries to find a way to make mobile ads work, Twitter is quietly cashing in. More than half of the company's revenue now comes from mobile, Shira Ovide of the Wall Street Journal reports. And, at least in the early going, Twitter ads appear to be more effective on mobile than they are on the desktop. Twitter ads are also the same on mobile and the desktop, which other forms of digital advertising aren't. This makes life easier for advertisers, who don't have to futz with different ad campaigns. The restaurant chain PF Chang ran a small time-sensitive...