Apple devices account for 4 out of 10 online ad impressions

Ad impressions as reported by Millennial Media, the largest independent online ad network, offer an imperfect measure of market share. But they do indicate the way things are trending. Google's Android now accounts for more than half (51%) of the ad impressions in the network, but that the share represented by Apple's iOS grew faster year over year (to 42% from 34%). Apple's iPad has a 55% tablet market share and the rest fighting for the remaining 44%. Bottom line: Apple remained the top manufacturer in Millennial's ad network, with its share of total impressions growing to 39.2% in the second quarter of 2013.