What does it mean when Philip Morris decreases its promotions?

Philip Morris won't be offering as many promotions as before. If they offer a promotion of $1 off a carton of 10 packs that normally costs $20 a carton, you pay $19, or effectively $1.90 per pack. However, if they stop offering the promotion, now you pay the full $20 per carton, or $2 per pack. The cost has effectively risen 10 cents per pack.