Basically any “Buy One Get One Free” style sale where instead of getting the second free you basically get the second for 99% off. (Note this only applies for getting stuff at 99% off, buy a burger get a second for a dollar doesn’t count but I’m including the dollar example for when you see sales of “Buy a $60 game and get the second for $1”)
Is there any real advantage in not just making the second free? Is there some weird tax thing going on? Does it somehow look better on the books if you make 1% more sales over a normal free promotion?