I wouldn't be able to say without sounding like a blind fan and getting flamed.
Lets just say I see a certain company as a threat to MY long time prefrence of gaming.

There are many similar websites to VG chartz -
like hidef.com which track media formats and
and then game leagues for
football ,soccer,hocky ,rugby , cricket etc
where people go to check "their" team performance on the league charts of course if they win or loose they get bragging rights to their friends when their team wins.
Its all the same in this case the teams are video game companies lie EA, sony, MS,Nintendo etc
And good sales performance (Both Projected and Current ) of an owned console can also translate to more future games releases, improved hardware revisions, better developer support and so on.

I like to see PS3 do well there are some very interesting things the Cell CPU can be used for (Like Folding for example) and more machines is better.

The past 8 years or so I have been around Sony fanboys who have flaunted the fact that their system was better. Now that Nintendo is on top again, I like the daily reminder :)

Because I own a Wii and I have invested in Nintendo's stock.

I love games, and i like to talk to people with the same interest rather than my mum or sister who know nothing about games or consoles, even if it mean talking to people from all over the world, i also make friends that i would have never made before.
Vgchartz is like a fourth home to me, lol even if i dont post much (shed a tear but its the truth).

Plus the software sale are very interesting. And i like economics.

I love stats and I love games.

We follow the gaming biz like other people follow their sporting teams.

 I love the irony given GC was a bit better console while PS3 is far superior then wii, yahh yahh i know what you mean but people rarely bother enought to get the right point across.

Because arguing over console sales is fun.

What kind of games are you into?  Seriously, even in it's best case scenario, the PS3 won't get a large quality or quantity advantage over the 360 this generation.  It is just too little too late.