I don’t know about you, but I get tired of using bad math to amp up an otherwise mundane value proposition. Yes, we know people are bad at math. That’s why states have lotteries (bad at math tax) to fund schools (that teach math). “Save 15%” sucks.” Save 15% or more” is more awesome in it’s infinite potential savings. FREE with the asterisk that tells people it’s slightly not-so-free, but is still FREE, so people are perfectly willing to pay $120 a month to have that free smartphone (that they could have bought for $200).
Unfortunately we marketers turn to these tried and true clichés way too quickly and far too often. We turn to the percent discount before having meaningful competition or make our new competitors look like the de facto standard when they are playing catch up by comparing (15% better) to them when we should simply focus on the brand or simply doing a better job of explaining “what’s in it for me?”
Oh, and answering that last question, “What’s in it for me?” is the toughest question in marketing.