Getting potential customers to your website or sales page is half the battle—getting them to follow through with a purchase (conversion) is the other. Conversion is an interesting art and science, especially when compared to the first part of the equation. Search engine optimization, pay-per-click and most other Internet marketing strategies are very much numbers games. It’s the endless pursuit of more backlinks, higher PageRank, more impressions, etc., etc. A website with a large number of links from authority websites naturally garners more traffic. That’s easy to understand. But when it comes to conversion, there are some aspects that seem to defy logic.

Take this one, for example. Which offer do you think would convert best: (A) 50 percent off (B) half off or (C) buy one get one free. If you guessed C—the almighty BOGO—then you guessed right. Studies and test conducted by scores of direct marketers back up the superiority of buy one get one free offers when compared to 50 percent off or half off deals. From a pure numbers basis, each deal offers the same thing. Fifty percent off a purchase of 12 ink cartridges is the same as half off of 12 ink cartridges or getting 12 ink cartridges for the price of six. It’s literally six of one, half dozen of the other. But there’s some kind of subconscious miscalculation occurring that tips the scale for a buyer more often when it’s a BOGO, rather than a discount.

Perhaps it’s the notion of getting something for free. There is always some mystery from a consumer’s standpoint as to how much any given product is really worth. Because of this, fifty percent off of an item that’s marked up 200 percent doesn’t seem like much of a deal. But with a buy one get one free offer, it’s more like they are getting one item for 100 percent off, rather than two items at 50 percent off. It’s fuzzy math, but in a world where we buy based on gut instincts and emotion more often than based on purely rational calculations, fuzzy math is what matters. For Internet businesses looking for a simple way to boost their conversions, it makes more sense to simply go with what works, even if it’s unclear why it works.

This, of course, makes the most sense for unit-based purchases, such as digital photo prints or bulk food, rather than services, such as surgery or tax preparation. If a buy one get one offer would logically swap out with your current discount offer, give it a shot and see how what happens to your conversion rate.