There’s a great AMEX offer for a $20 statement credit when you spend $50+ at Jet.com. Play it right and that’s ~40% off your purchase! (Check your accounts online, or sync via Twitter with #AmexJet.)
But here’s something I noticed.
There’s no mention of having to spend $50 in 1 transaction.
There are several other AMEX Offers that do say you have to spend the required amount all in 1 go, like the one for Delivery.com.