Intermarché has a 1+1 promo on clips of Cubanisto (Tequila flavored beer). Then the 3 packs of beer themselves had 2+1 printed on the case.
There is no print to say the promos cannot be combined. So of course I expect to pay for 2 bottles and get 4 gratis. Other grocery stores work that way. If there is a promo of that discounts multiple clips and then there are also in-pack promos, you can end up buying fewer bottles than what they give for free.
In the case of Intermarché the register is a bit extra diligent and works out which promo is better then makes adjustments to ensure the promos are not combined.
I’m not following your math. It sounds like since they’re already bundled together, they’re already priced appropriately, e.g. a 3 pack for the price of 2. So I would expect you’d get 5 for the price of 3. The “free” one is already included in the pack.
Quick edit: oh I see they advertised 1 for 1 packs not two pack beers. You’re right that is silly.
The receipt shows:
Cubanisto: €3.69
Cubanisto: €3.69
Cubanisto promo: -€2.39
When I saw that I thought something is wrong here… but then I realised the register took the math far enough to offset the in-pack promo. In the end I paid the same price per liter that the weekly ad showed. I think I did not even notice the in-pack 2+1 promo when I grabbed it. So I got the price was expecting and was actually fooled by the receipt.
But anyone could have seen the in-pack promo and expected to get both promos together, and they could have bought the beer on that basis (as I have in the past). And they would have been burnt. There is no regulator for this in Belgium.