Be Aware Of The ‘Unit Effect’ To Avoid Marketing Tricks

Be Aware Of The ‘Unit Effect’ To Avoid Marketing Tricks

We’ve shown you one way in which numbers can play tricks with our heads, and researchers have just found another that shows we prefer larger numbers — even when they’re equal to a smaller number of a different unit.

The “unit effect”, as it’s called, says that even if you’re aware of the units in a measurement, your mind will still put more emphasis on the size of a number, rather than the value it carries:

Consumers will readily attach weight to completely fictitious product statistics, preferring items with the most bogomips, even if they have no idea of what the significance of that figure is. That may be disappointing, but apparently it’s even worse than that-even when they do know what the units are, people tend to prefer a bigger number. As a newly released study shows, people would rather pay for expedited service to get things in 31 days than they would to get it in one month.

Of course it’s counter-intuitive, but if you aren’t actively converting that measurement to other units, you aren’t aware of your biases. Of course, as soon as you become aware of these biases, the unit effect goes away — so the next time you’re told something will, say, ship in 31 days, do a quick check in your brain to see if that fits another familiar unit that casts a different light on the result. You may find you escape some marketing tricks by doing so. Hit the link to read more. Photo by Biking Nikon OGG.

The “Unit Effect” Makes 31 Days Seem Better Than a Month [Ars Technica]


  • Honestly, I’ve never had a problem with identifying the “actual” value of whats being offered. It’s no secret that caryards will sell cars at $19,999 because many peoples logic will compare the price within the “ump-teen thousand dollar” group, not the “20-something thousand dollar” group.

    Theres a dead simple remedy to this to see trick pricing and marketing for what it really is – ALWAYS round up.

    No retailer is ever going to purposefully price an item at the very bottom of a given price range, they’ll sooner drop it a little further so it scrapes in at the very top of the lower price range.

    Same also applies for, in the case of this article, a duration or turnaround time. If something is being sold as a “31 day turnaround”, round it up to a month.

  • I would agree that the 31 days conveys more precision which is what would be more attractive in this case.

    However i’m sure we’ve all had encounters with ridiculous telesales representatives that try to use the “unit effect” to an extreme…
    My particular experience springs to mind where I have had someone argue with me for well over 5 minutes (god knows how I let them talk for that long) that their 700 MEGABYTE DSL Download was much more than my existing 100 GIGABYTE connection that I had at home….

    …. On second thoughts… Maybe this telesales rep was just simple….?

  • I’ve long mentally converted supermarket prices to dollars per kilo/litre/whatever as I’m shopping, in order to avoid packaging which is mostly air or the volume-shrinking effects of various container shapes. Helps to see through purported ‘sales’ prices, too.

    In the last few years, though, I’ve noticed some supermarkets actually doing this for you in small print on the shelf label. Not for every product, but for many of them.

    Of course, if you really do personally prefer brand X over brand Y, it’s not going to make a lot of difference if brand Y is two cents cheaper.

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