Looking at iPad market share, John Gruber says:

What they’re calling market share is really “shipment share”. I don’t think that’s what most people think of as market share. By their metric, a company could take the market share lead by shipping 10 million tablets and selling none of them to customers.

This is exactly what I point out when talking about RIM and the PlayBook. RIM says they shipped 500,000 PlayBooks in its last fiscal quarter — for all we know they could be sitting in a warehouse somewhere. Shipped doesn’t mean sales.