Discover give 5% cb currently at Bed Bath Beyond.
Make a large purchase, receive the miles, 5%, and interest spread (very minimal).
That might be what he's referring to.
His point just was that it's a way of getting an interest free loan for almost 2 months
A 50-day interest-free loan of, what, $10,000 beats points/thresholds 99 out of 100 times?
Rubbish.
Where can you get a return of about $4500-5000 (what I've gotten for a single CC bonus) on an investment of a few thousand dollars in 50 days?
And, even if you could get such a return in this market, you'd presumably be exposed to tremendous downside risk. Guess what happens in 50 days whether your lose the "free money" or not - the bill comes due. And, a few months at 30% interest will exacerbate whatever loss you've incurred.
If you're only talking about the cashback aspect, you've a)
not beat out the points/threshold aspect, and b)
...I'd point you to the original comment. There are other ways to meet spending thresholds or rack up points that are probably less... exploitative/damning.
I've personally benefited from the BBB cash-back policy, (as I'm sure others on DDF have), and my benefits (being able to get cash back on wedding presents) was worth way more to me than a few % cashback. Exploiting it like this is a sure-fire way to get it changed.