1. Buy 3 tires and get one free! - or -2. Get 25% off a set of four new tires! - or -3. Pay just 75% of the price of a set of four new tires!
1. One person will bite on "buy 3 get one FREE!" because they like the word "FREE" and think they are really getting something-for-nothing. They don't like the other two offers, because those are merely discounts or price adjustments without a "Freebie" involved.
2. Another person will bite on "25% OFF!" because they are getting a discount (likely a couponer type of person) and they distrust the idea that anything is "FREE" or that they think the free item is of inferior quality. The third option - paying is not attractive to them.3. Yet another person will bite on the "pay 75%" bit - although this is the smallest of the three groups because it has the word "pay" in it, and not "FREE" or "OFF". He likes the idea of the lower price but dislikes the coupon-type idea of "25% off" or the gimmick of "FREE" things.