Apologies, bad choice of word on my part. I should have said "akin" rather than "related". The point I was trying to make is that whilst those companies offer

Apologies, bad choice of word on my part. I should have said "akin" rather than "related". The point I was trying to make is that whilst those companies offer a membership incentive structure its not a true co-op and you don't have an ownership stake in the company. You just receive some member benefits like cash back and discount coupons - similar to your credit card company giving you air miles.