I would say that fads serves more to damper than help the sales of the consoles...
Wiimote not being supported well by 3rd parties could have prevented Wii to sustain sales, Kinect mandatory X1 damped its sales, Sega-CD made Saturn sales lower, PS3 bluray making higher price impacted PS3 sales, etc...
Focusing in the games first is what made NES, Genesis, SNES, PS1, 2, 4, X360 successes...
duduspace11 "Well, since we are estimating costs, Pokemon Red/Blue did cost Nintendo about $50m to make back in 1996"
http://gamrconnect.vgchartz.com/post.php?id=8808363
Mr Puggsly: "Hehe, I said good profit. You said big profit. Frankly, not losing money is what I meant by good. Don't get hung up on semantics"
http://gamrconnect.vgchartz.com/post.php?id=9008994
Azzanation: "PS5 wouldn't sold out at launch without scalpers."