We've been longtime KOA members. The KOA discount is only 10% but if you stay at enough of them you can cover the annual cost ($30) with the discounts. Recently they've added a rewards program on top of the discount (earn points that you can redeem for camping--so far, for us, we earn enough points to pay for a night or two camping every three years or so).
They also recently have added coupon programs:
https://koa.com/value-kard-rewards/coupons/
I know no one asked about KOA but the subject is "and other clubs"
Thor Forums
