Fred Wilson makes the distinction between the ability to sell and actual product-market fit:
From http://www.avc.com/a_vc/2013/03/revenue-traction-doesnt-mean-product-market-fit.htmlNot only does the organization need to learn how customers will acquire and use the product, it is also true that the product itself may not be exactly what the market wants. In other words, launching a product is not the same thing as achieving product market fit.
The full paper his article is inspired from is at http://www.signallake.com/innovation/SalesLearningCurve.pdf