Fortune: Google is amping up its mobile advertising efforts to address challenges, touting new products such as a “buy button,” which allows people to shop directly within Google products on mobile, as well as mobile-friendly YouTube ads and elaborate, conversion-friendly search results for things like hotels and cars. The company is also touting strong performance on YouTube, which has been under increasing pressure as competitors, most notably Facebook, gain traction. “Watch time,” YouTube’s metric for measuring usage, grew 60% over the second quarter of last year, and on mobile, watch time has more than doubled.