Wonder why mobile monetization is still lagging as Kleiner Perkins partner Mary Meeker helpfully pointed out earlier this year? Well, one reason may be that many of the clicks on mobile ads are useless, the product of an increasing amount of fraud as well as a lot of inadvertent actions, said Trademob, a German mobile app marketing platform. The company, which is in the midst of opening offices in San Francisco and New York, shared some new research with GigaOM, finding that 40 percent of clicks are essentially worthless, creating a conversion rate to install an app from an app store of less than 0.1 percent. Trademob found that 22 percent of clicks are accidental, while 18 percent are fraudulent. That could be one thing holding back mobile advertising as some advertisers question how effective their spend is on mobile.