^Also, different metrics define success or failure. Some examples:
Absolute Sales volumes: Many will agree the PS2 is a monstrous success due to sheer platform sales volume.
Profit/Loss measures: Some will say the 3DS first year is a failure because the 3DS did not make profit for Nintendo, rather it likely caused losses. In that case it will be said so, even if absolute sales volume is high. It can be also used against the PS3 and in favor of the Wii.
Relative Sales volumes: Some may argue that the Wii is not the full success it could've been by absorbing HD market via basic HD support. In that case, despite high absolute sales volumes of 90+M, relative to the HD consoles separately, or even relative to the HD consoles combined, the Wii may be considered a mild success.
However, in a case where the market altogether shrinks yet one platform largely demolishes the competition by holding a marketshare of say 70%+ (as was the case for the PS2 in europe), then it could lead to much more interesting questions as "What caused the market to shrink? Was it the doing of the main market players, or was it the market itself?" and ultimately "Was the leading manufacturer winner, or loser in the end?" Food for thought.
In that sense, comparing gen 8 to gen 7 (3DS to DS) could lead to fruitful discussion as to the state of affairs of the market.
