From little things, big things grow?

A friend who understands something of the opaque world of finance tells me that the fortunes of a certain large bookselling chain have improved dramatically in the past six months. From being well and truly in the red, said company has now reported a very healthy half-yearly profit. How much of this good fortune can be apportioned to the company’s slightly controversial practice of adding a few cents here and there above RRP to much of its backlist, my correspondent wonders?