Twitter (TWTR) is down nearly 12% after hours following a Q1 EPS beat and a revenue miss. The key metric is the sequential increase in MAUs to 310 million, up from 305 million in Q4. The metric saw the biggest sequential increase in the last year and should only grow along with Periscope and the NFL package. Buy this dip as Twitter will figure out how to increase advertising revenues as long as the user base is strong and growing. Disclosure: Long TWTR