Facebook’s mobile monthly active user base climb 54 percent to 751 million people (including 189 million people who only check Facebook from their mobile devices, up 128 percent year-over-year), but once again mobile jumped as a percentage of Facebook’s ad revenue, having gone from 0 percent in Q1 2012 to 14 percent in Q3 to 23 percent in Q4 to 30 percent in Q1 2013. Desktop ad revenue "stayed flat," Ebersman said, before qualifying the stagnation. "Flat desktop revenue does not reflect a particular trend relative to desktop demand. Instead, more inventory is being shown on mobile because that’s where people are spending more time," he said.