Geniek,
I suspect you may run into problems similar to other Style Producers such as Midi Spot (and Korg and Yamaha themselves) due to the ease that styles, once purchased, can be shared with others...pirated, in other words.
Do you have some sort of file protection system to prevent this from happening?
Ian
  Yes, we know how, and we can protect our styles to Ketron, build package .ksi (Userstyle.ksi) and installation script  00Kinstal .... just like Ketron in their updates, but then you need to distribute this style on pendrive and it burdensome and don't cost-effective in the case of one or two styles
Not every customer wants to buy a whole pack of ten or  twenty styles (on pendrive)  because  he needs  only  one or two styles
We count on honesty and respect for our work to our clients
We trust them 

Everyone has their own conscience 
