Dave, I do not believe for a second that's how it works. Once installed, it is immediately used for
PR selling the good neighborliness factor, yes. Absolutely no issues with that but it does not quench my curiosity.
The costs of certifying an element protruding into the airflow on a wing are huge, and somebody needs to pay for that. Especially if we both guess most will buy it there needs to be a widely applicable positive ROI somewhere. Going one step deeper, the ROI (and a profit margin on top) had surely been identified before authorizing the development of the gadget in the first place.
I am thinking of regulatory compliance with future noise limitations, and wonder what the fuel impact is over a year's worth of flying. That needs to be offset too.
EDIT: silently hoping to be wrong...