The Internet.
There must be dozens, hundreds or even thousands of sites dedicated to particular consoles all blowing their respective trumpet about how great or amazing a particular console is. Forums are everywhere allowing people to express themselves or vent frustrations which fuel others into responding.
The last generation (GC, PS2, XBOX) was the start of it when the Internet exploded and people started to find online communities, which are everywhere now!
Prior to that (N64, PS1, Genesis, Master System etc) there was no way for people to really spa off each other!
Hell even this (fantastic) site fuels all sorts of speculation about future sales trends with its statistics/tools which will naturally attract anyone interested in quoting figures etc.
Fanboyism is here to stay!
Next generation expect stabbings and shootings!
