Imagine this — You pick up the latest flat-screen TV on Amazon, then, a week later, notice it costs $100 less at Best Buy. Sure, you should have done your research, but wouldn’t it be great if your someone — perhaps your bank — could go back and get you the lowest price for the item?

Yes, that would be a cool card reward, and the thing is, Citibank already does this. It’s just that no one seems to know about it.

Citi Price Rewind, as explained in the video below, allows users to register recent purchases with their Citi cards online. The video was posted just last week. Citi then searches merchant sites for 60 days, and if it finds a lower price, refunds your overpayment. The service launched for the 2014 holiday season and even had a TV spot.

But our unscientific survey of two Citi cardholders revealed neither was aware of it, which means Citi is missing out on some love from its own customers, because frankly, this is an amazing feature.

Some points of interest about the video below, which may be an attempt to rectify the situation:

• Users have 60 days to request a refund of up to $300 per item from Citi. Specifically, after the purchase is registered with Citi, the bank searches for a lower price for 60 days, then informs the user of the result and issues a credit or cuts a check. What sort of deal does Citi cut with the merchant to make this happen? The video does not indicate it is limited to certain merchants or select items.
• Users must log into Citi online banking to put in a claim. This is a pretty powerful incentive for a customer to manage his account online, if he is not already doing so.
• The video notes that, “When you use your card, Citi only sees the merchant and total amount you spent.” (Paging Nerture.) Banks need more insight than this into consumers’ spending. If consumers log enough purchases, Citi will get just a tiny bit more.

When a cool feature is introduced and goes largely unremarked, what’s a bank to do? Perhaps this video is the start of a new information campaign about Price Rewind. (It had only been viewed 78 times when we first noticed it.)

Then again, some customers do, in fact, know about the product. Citi indicates on its Price Rewind site that it has issued nearly 25,000 refunds totally $787,000 in 2015, with an average refund value of $31.