Tie-ratio, in my opinion, is the most valuable indicator of success. It shows which consoles people are actually buying games for and therefore helps distinguish between consoles poeple buy and seldomly use, and consoles people buy and continually use and enjoy. For those who don't know, tie-ratio is the average number of games each owner of the different consoles owns (hardware sales divided by software sales).
Here's the tie-ratios of all of the home consoles this gen...
X360: 9.77
PS3: 8.75
Wii: 8.34
And here's the tie-ratios for the portables of this gen...
DS: 5.03
PSP: 3.70








My prediction threads:
Wii U will sell under 40m units (made on 14th September 2012)
PS Vita will sell under 20m units (made on 30th September 2012)
Wii U will sell under 7m in 2013 - I was right









