There are many different types of neurofeedback. The one you are referring to is at this web site. http://www.eeginfo-europe.com/neurof...e/cygnetr.html
The link you provided went to the main page of eeginfo.com

I can not figure out how this one works. There are two basic types, volitional and non-volitional. In volitional, the subject tries to modify the brain wave forms with cognitive effort. In non-volitional, the system provides some sort of stimulus, either as a reward or as a 'pushed correction' with sound, light, electromagnetic pulse, electrical pulse, etc.

The web page shows a game interface but the description mentions the ability to change the reward frequency. So, I am confused.

Most neurofeedback systems can measure improvements by changes in waveform at rest. The goal is usually for the non-volitional system to retrain the brain so it maintains the desired waveform.

The volitional systems are focused on teaching the subject how to cognitively modify the wave forms. With enough practice, the subject learns to maintain the desired waveforms without effort.

If you are not sensing a benefit and the system is not indicating an improvement in waveforms, it would appear to not be making a difference. But, if you are willing to keep paying, they are probably willing to keep trying.