Originally Posted by gleto
So why do others such as tuneboy and bazzaz sell modules
To make money.
Does TuneBoy actually sell a module of some kind nowadays? At least before it was just a very expensive cable, similar to the free TuneECU in functionality.
Piggyback modules are better/easier for inexperienced tuners as they provide possibility to live tune on dyno, and also they have many helper apps for the dyno operator.
As far as end result is concerned tuning bike's own ECU with TuneECU (or TuneBoy if you want to waste your cash) will yield better results. If the tuner knows his trade.