170 million people in the US watched videos online in February, averaging 13.6 hours per viewer. That’s according to comScore’s latest metrics, which reveal more than five billion ‘viewing sessions’ from US users alone in February. YouTube remains the 900lb gorilla in the online video space, with 141 million unique viewers for that month. Behind come Microsoft sites (48.8 million) and Yahoo sites (46.7 million), followed by Facebook (46.7 million) and Vevo (45.9 million). On the latter specifically, there were more than 222,000 viewing sessions in February, meaning each visitor spent an average of 86.7 minutes watching videos on Vevo that month.