In the past the PS3 has been the biggest victim of being under tracked. Fortunately PS3 sales numbers get adjusted upwards when the latest shipment figures are released.
Under tracking is not a problem when your console system is not on the wrong end of it. 360 is usually over tracked and its numbers are adjusted downwards wwhen the latest shipments figures are released.
Console shipment figures exceeding sales data is impossible: sales data is around 1 or 2 months behind the shipment figures.
No one likes seeing their favourite console system being under tracked.







