Acer's refusal to acknowledge the iPad's competition before its refocus on mobile cost it dearly in the winter, IDC said in a preliminary market share breakdown on Wednesday. The Taiwan PC builder's shipments to the US dropped a steep 42.1 percent versus a year ago to hit just 1.33 million, or 8.3 percent. Apple stayed in fourth place, but its success with the Mac and Acer's failure led it to jump from seven percent in early 2010 to 8.5 percent, or about 1.38 million Macs.
