John F.

If you want that little extra reward for a purchase, you can use BeFrugal or Capital One Shopping (I don't consider Ibotta or Honey to be competitive currently).
BeFrugal usually wins in terms of the percentage back and their system has some slick and attractive features, like the ability to add user notes to a shopping trip. You WILL need them later if you have trouble actually getting your rewards... and you WILL have trouble.

BeFrugal's greatest failing is that their customer service is not your partner.
They are your adversary.
Think of them as an insurance company trying every loophole to NOT pay out. If there is an error, they will not try to find or fix it. They do the bare minimum and blanket themselves with the excuse "If we don't get paid, we can't pay you". Imagine if your boss said that to you? "I can't give you a paycheck this week 'cause business is slow."

BeFrugal, boss, I sympathize with you not getting paid, but use customers as a tool to FIX errors, don't just deny paying them what you promised.

Capital One Shopping seems to usually take a more sympathetic approach to issues. If they find the system failed, they will often take the hit in the name of customer service.

That will NEVER happen at BeFrugal. It makes you, the customer, want to just take everything you bought with BeFrugal and just return it (oh course, they won't pay you until long after the return window is closed*, so that is not an option).

So, If you use BeFrugal, be prepared to let 25% of your earned rewards get lost in the system OR be prepared to diligently and actively fight, research, and document (but even that will only get you so far: "we don't get paid, you don't get paid" is the BeFrugal motto).

*Another common complaint about BeFrugal is how aggressively long the payout window is. I currently, as an example, have a payout from a purchase over 100 days ago verified and just in payout limbo. I have been asked to at least wait 120 days... 4 months! A third of a year! But I could live with that IF they actually cared about me.

EDIT after BeFrugal's response on 12/28/2023: You are a separate company from the merchants. You exist to encourage sales through promised discounts. You are not a non-profit. Your company needs to STAND BY promises and FIX errors. You need to work to improve, and use customer feedback and mishaps to guide that. In my 20+ support tickets, you have never made any attempt to fix a specific issue with a specific merchant beyond cutting and pasting an "advice script" (which is helpful ticket #1, but just insulting by ticket #20) and saying "Sorry, tough luck. It is the merchant's fault, not ours, now go away. You will not get what was promised". Actually, I am not sure you have even said sorry.

You need to admit to yourselves that too many cash-back attempts just get lost*. When that happens, the merchant wins (with a sale) and you win (by continuing to have a relationship with the merchant and customers and making money somewhere). The only loser is the customer who wonders 3 months later what ever happened to that 8% cash back they were promised.

*I fear this "% of expected cashback failure" is not only known, it is an integral part of your business model.
"... and customers won't even notice they never got their rewards..."

You can get a little extra discount with CardCash for a purchase you KNOW you will not return, but NEVER buy a card to give as a gift or to save for later. I have had too many situations where the seller continues to use the card and it is $0 when you get around to using it. Do you want your father to ask why you gave him a blank gift card for Father's day? Was your childhood that terrible!?! There is a 'guarantee' but it is a short window. A 5% extra savings is not worth the hassle of filing a ticket and proving you didn't use the card. I learned the hard way so you could learn the easy way.

You can get a little extra discount with Raise for a purchase you KNOW you will not return, but NEVER buy a card to give as a gift or to save for later. I have had too many situations where the seller continues to use the card and it is $0 when you get around to using it. Do you want your father to ask why you gave him a blank gift card for Father's day? Was your childhood that terrible!?! There is a 'guarantee' but it is a short window. A 5% extra savings is not worth the hassle of filing a ticket and proving you didn't use the card. I learned the hard way so you could learn the easy way.