FORTUNE — One of the surprises in ComScore’s chart-packed Mobile Future in Focus “webinar” Wednesday was the relative sizes of the orange Amazon (AMZN) and red Samsung bands in the chart above.
Apple (AAPL) maintained its position as the No. 1 tablet manufacturer, but in battle for dominance among the Android tablet makers in the U.S. market — which is what ComScore is measuring here — Amazon is crushing Samsung.
In the worldwide market, where Amazon has a far smaller presence, the relative positions are reversed. According to IDC, Apple was still the leader with a 43.6% share of shipments in Q4 2012 , followed by Samsung (15.1%) and then Amazon (11.5%).
Take these estimates with a grain of salt since Samsung no longer reports sales or shipment numbers and Amazon never did.