Two years ago my wife, daughter and I got a cheap $78 RT SDF-ORD on DL for an Easter weekend. We volunteered and all 3 were bumped
and received 3 RT anywhere DL flys in the lower 48 plus were moved to First class on the next flight just a couple of hours later.
That Summer we used the free tickets to fly to Seattle for a great cruise to Alaska. On our flights back we had to change planes in Atlanta due to a spill in the Cargo Hold of our original plane. When we returned home we each received a $50 flight credit because of the delay! So for $78 we got First Class SDF-ORD, Round trip SDF-SEA and $50 off our next flight! I only regret not buying a lottery ticket that day!