This document provides statistics and sales estimates for various digital distribution platforms, including PlayStation Network, Xbox Live Arcade, and WiiWare. It notes that PSN has had over $180 million in cumulative sales and that top games have sold tens of thousands of units. XBLA games reportedly sell hundreds of thousands of units on average, with some titles exceeding 500,000 sales. WiiWare sales are harder to quantify but some games are estimated in the hundreds of thousands as well, though many likely sell under 10,000 units.

2. Independent Games & Sales: Stats 101 Simon Carless [IGF Chairman, Game Developer magazine/Gamasutra publisher.]