Sales of Apple's (AAPL - News) tablet computer are projected to jump more than 90% this year, although growth is expected to drop to around 12% a year by 2015. Market research firm eMarketer forecast Apple will sell 53.2 mil iPads this year, driven largely by 1st time purchases. But that's down from 144% unit growth in '11. Also, the number of U.S. consumers who use tablets at least once a month will jump 106.5% this year, says the firm, but that's down from 158.6% last year. EMarketer sees growth falling to 32.6% next year, 15.1% in '14 and 11.9% in '15 as sales of Samsung and others using Google's (GOOG - News) Android operating system ramp. Apple shares fell 1.6%.