Samsung on Wednesday let slip that it had shipped two million Galaxy Tab devices in the roughly three months it had been on sale in October. The figure, reached just this week, represented a doubling of the tablet's sales rate, as it had only delivered one million in two months at the start of December. It credited the boost to the sheer exposure of the Android tablet, which was on sale through 200 carriers in 94 countries and could be found unlocked in some areas.