Bill Ready, who led the company through its sale, says that mobile conversion rates are still far off from where they are on the desktop web. That’s partially because it’s a lot more tedious to enter or re-enter credit card information on mobile devices. Ready says that more than half of e-commerce shopping experiences happen on mobile devices, but only 10 to 15 percent of purchases occur on smartphones. “The reason for that gap is that there’s a two-thirds to 75 percent fall off in conversion,” Ready said. “People just bail out.” But after months of tests, Braintree is unveiling a way for people to pay across different apps with a single touch, which eliminates the need for usernames and passwords.