Tablet dollars: Android passed Apple for first time in Q3 by Philip Elmer-DeWitt @FortuneMagazine November 15, 2013, 1:56 PM EDT E-mail Tweet Facebook Google Plus Linkedin Share icons Estimated share of tablet shipments by quarter. Source: IDC FORTUNE — Apple AAPL investors have long taken comfort in the fact that even if its share of tablet shipments fell behind Android’s in a particular quarter, the company still took home the lion’s share of tablet revenues. That’s no longer true, says Morgan Stanley’s Katy Huberty. Working from the tracking numbers IDC released two weeks ago — which reported that Apple’s share of tablet shipments in the September quarter had fallen below 30%, their lowest level yet — Huberty calculated that the iPad’s share of global tablet revenues hit an even more troubling milestone: “For the first time,” she wrote in a note to clients Friday, “Android devices accounted for a greater share of the market in revenue terms than iOS. Android revenue share reached 46.2% in 3Q13, for the first time exceeding iPad share of 45.6%. Android’s unit share grew to 66.7% from 58.5% a year ago, largely driven by Samsung and Lenovo, while iPad share declined to 29.7% from 40.2%.” IDC attributed the iPad shipment falloff to Apple’s decision in late 2012 to move all its product launches to the pre-Christmas quarter — which meant customers holding out for a new iPad had to wait a full year. But with the iPad Air and Retina iPad mini moving briskly, both IDC and Gartner expect Apple to enjoy what IDC called “robust shipment growth” in the December quarter. UPDATE: To answer several readers’ questions… Neither Morgan Stanley nor IDC offers an estimate of Apple’s share of tablet profits Huberty does not explain how she extrapolates revenue share from IDC’s shipment numbers IDC does not explain how it estimates tablet shipments for a company like Samsung, which unlike Apple, never says how many tablets it ships. Or sells.