How much does it pay? It depends. The fees start at 4% of the purchase price, but if your referrals result in 7 or more purchases in a month you make 6%. People who are buying stuff already buy following your link. It literally costs them nothing to support your organization.
Another positive. You get paid after accumulating only $10 in referral fees! Payment can be Amazon gift cards, direct deposit into an account, or a check (but there are other caveats with a check).
The only real work you or your club members need to do is publicize your link!!! Buying something for Mother's Day? Why not try out my search box. My students thank you!