Basically, the reason I did this was to identify key factors in what makes a game (on average), have a certain kind of leg, and I think the charts show that.
In the case of PS3, no software sold @ launch (since the tier rate was combined 1.0), which eschewed their data hugely, whereas the X360 and Wii launches saw great software sellthrough, to give most games, normal legs.
Also, having said this, we can see the majority of games, regardless of format, fit into 3.5-4.5 legs. Even Zelda:TP almost fits into this. Obviously, there are tons of variations, and tons of games that beat this (like Wii Play, already).
There are a few games that have no 2007 data, but I KNOW there is 2k7 data on the games at some point - I just haven't found the data yet, as ioi only shows the top 200 games of the year (hey ioi, mind changing that?).
And finally, we can see that some games, ie Madden and NCAA08, are going to have abysmal legs. This will certainly help us to extrapolate final sales.
But like you said, creating a graph for various games, would be a good idea. I actually have a chart of millionsellers for the X360, and the charts are pretty neat.
Nevertheless, I probably will re-do those charts, factoring in PS3 and Wii US/NA millionsellers (Zelda:TP, Wii Play, R:FOM).
Realilistically, for any game to go into a certain multiplier, you only need about 4-5 weeks of data to give a near-exact end total, because by then, you can understand where it's trending toward - games like Wii Play and Guitar Hero show a totally different sales curve vs. Mario Party 8 and Crackdown.
Back from the dead, I'm afraid.
