Estimates of the number of businesses eligible to take the tax credit have ranged from 1.4 million to 4 million companies, but in May, the Government Accountability Office reported that only 170,300 firms actually claimed the credit in 2010. Of these, only a small fraction, 17 percent, were able to claim the whole credit….
So why has the credit fallen short of expectations? The G.A.O. concluded that the credit was too small to sway business owners. Moreover, it said, claiming the credit is a task so complicated as to discourage many companies from trying.