Despite being the only major tablet alternative for people who don’t want to bite into Apple, Android has clearly had little impact on the tablet market. IDC’s second-quarter tablet report shows that more than two-thirds of all tablet shipments originated in Cupertino, and even those numbers don’t tell the full story. IDC (which is owned by PCWorld’s parent company IDG) and other top research firms track tablet shipments to retailers, not tablet sales to customers. So when you take into account that some variable proportion of shipped Android tablets languish unsold on retailers’ shelves, Android’s situation may be even bleaker than IDC’s numbers suggest.