I applied for the first Discover It in 2017, and I still have that one. After my year of cash back match was up, I applied for a 2nd Discover It and was approved. Another year of cash back match goes by. I found that you can't have more than two Discover It cards, so I canceled the newer one. Before canceling, they let me move the available credit from the newer card to the older card, so now the older card has a large limit. A few days after canceling, I applied for a 3rd Discover It and was approved. Another year of cash back match (and 14 months of 0% interest) goes by.
I canceled the 3rd card on Saturday. And I just applied for the 4th card today on Monday and was approved again.
I have a reoccuring charge on the older card to keep it active, but otherwise put most of my spending through the newer Discover card since it's essentially a 2% everything 10% rotating card with the cashback match. I have other 5% cards, but if the spending doesn't fall into one of those categories, then it goes to Discover.
My Citi Double Cash card was a goal card of mine, but it will not be seeing much use for another year since the Discover rewards structure is a little more generous than Citi's when you redeem it for gift cards.
I'm curious if anyone has been doing this for even longer. I wonder if there will come a time that they say "No more cash back match for you!" But as long as it keeps working, I guess I'll keep doing it every year.
Congratulations on your 4th card.
Initially after reading the title of the thread I thought to myself, WOW!
At the same time, Congrats on the very nice Promo and approval!
Not for longer but @AverageJoesCredit has done the multiple discover thing awhile back for additional years of double cashback...
-J
I would suspect they are going to shut this door down before long. Grats on getting the 4th card and the match again 
Congratulations on your approval!
Congrats! Ride that train while it lasts! I wouldn't, however, be surprised to see the new account(s) closed for "churning."
Best of luck!
