There are a number of airlines that offer similar programmes with a varying number of nights in the stopover city/country but it's def an option worth exploring to visit two cities on your bucketlist. You might even be able to take a train or bus between the two 😉

^ This is a great option from Jamaica btw.

For anyone flying on COPA, that's a great way to do a 2-in-1 trip. Using COPA's stopover programme, you can visit anywhere that COPA flies plus up to 6 nights in Panama for only ~US$50 more on airfare. (It says free but technically you have to pay an airport fee twice).

Examples:
Park City + Denver + Breckenridge
Paris + Amsterdam + Bordeaux + Brussels
Trinidad + Panama
One year I even did NOLA + Vegas + Sonoma