Over the past few days, I’ve noticed a rather odd promotional campaign. First, an online grocer was offering a 25% discount on certain wines if you purchased at least six bottles. Then, I saw the exact same discount being offered in the wine section of my local pharmacy. Six bottles seemed like a strange minimum quantity, which made me think about the mechanics of this campaign.

Looking at the basic math, a 25% discount on six bottles is the same as buying 4.5 bottles and getting 1.5 for free. Of course, you can’t purchase part of a bottle, so a better comparison would be a promotion for buy three, get one free. However, that approach would mean the minimum order size is only four bottles, rather than six.

Why did the retailer or manufacturer adopt this strategy? My guess is that most people buy between one and five bottles of wine at once, and the goal here was to get them in the habit of buying larger quantities instead. As for whether the 25% off approach is more effective than something like buy six, get two free, you’d probably have to test it both ways to find out for sure. And given how much six bottles of wine weighs, it probably wouldn’t be a bad idea to think about including a free wine tote to sweeten the deal.