Why aren’t more people doing that? Sounds like a money maker.
This was 8 years ago.
I assume the folks at the various institutions figured this out and put some limits or prohibitions on it.
Like maybe you can’t buy millions of dollars of gift cards with your AMEX.
Not sure though.
From the article the physicist found out about it from online sources and tried it as an experiment that worked. My guess is you need to find a supermarket chain that will let you turn their gift cards into money orders. The other key is not to be left holding onto gift cards you can't convert to cash when the supermarket decides to change its policy on converting gift cards to money orders.