I recently went into my local Ralphs (aka Kroger) to buy eBay Gift Cards with double rewards:
I buy these cards with my rewards credit card which gives me back 1% (but some people have 2% cards like Fidelity, Schwab, or PerkStreet. AmEx Accelerated Rewards is 1.25%).
Then I go to BigCrumbs which directs me to eBay
Then I go to Upromise which leads me to eBay:
I get eBay Bucks back and maybe 2x if I buy from a TSR or Bill Me Later that is eligible
1%-2% rewards credit card
36% of seller FVF paid back
2% eBay Bucks (or 4% if you buy from a 2x seller)
So, you end up with 7% and above in discounts in various forms.
Kroger requires you to buy $250 worth of gift cards to meet their quarterly minimum of 500 points to get a payout of $5.
Rewards credit card usually needs 2500 points before you can redeem for full value.
The BigCrumbs pays out monthly via Paypal.
Upromise is for college savings (529)
2% eBay Bucks is paid out quarterly, and requires Paypal, with a max back of $500 per calendar year.