Well, recently many stores in the city offered their Shopping NIghts. These are special nights, in which the store closes later than usual (about 9pm), offers special discounts (20% is the average). and has several ammenities, such as a live band.
The most acclaimed one in Panama City is Felix´s Shopping Night. I really don´t know why, since they do not offer special discounts on the items you're buying. Instead they give you a $10 discount coupon for your next buy, which can be redemmed that night, but just on the item you buy.
This year the store (on Vía España) was really crowded with long lanes and people buying like crazy, with glasses of wine (maybe cheap or not, I don´t know, but it´s free). I just stayed a little while.
Collins and Tommy Hilfigher had their special night of offers. These stores had 20% off the original price in the merchandise, which i think is better than the other store. Collins is a department store, like Felix, but they sell somewhat different merchandise, much cheaper than Felixs'. But they also sell brands like Kenneth Cole, Diesel, and Polo... By the way, the prices of the Diesel items are cheaper in Collins than in the Flaship Store itself.
Well, that´s all i can report by now.