The Blemishing Effect
The blemishing effect is the finding that a small negative detail can make a product more appealing, but only for people paying little attention, and only when the negative comes after the positives. For careful readers, the same detail backfires.
What it is
Danit Ein-Gar, Baba Shiv and Zakary Tormala reported four studies in the Journal of Consumer Research in 2012. In one, 141 people read about hiking boots; for some, the description ended by saying they came in only two colours. Among low-effort readers, purchase intentions rose from 3.29 to 4.26 on a seven-point scale. Among high-effort readers they fell from 4.24 to 3.36.
A field study found students distracted before an exam bought more of a chocolate bar described as a bit broken, while undistracted students bought less of it. A further study found the effect only when the negative followed the positives.
In effect
A minor flaw placed after strong claims can make the claims seem more credible to someone skimming. It is one reason a few mild negative reviews among many positive ones can help, and why the same flaw on a comparison page, where people read closely, simply looks like a flaw.
What it does not say
It does not cover serious flaws or safety issues. All the negatives tested were minor and beside the point of the purchase.
It does not apply to careful readers, for whom the effect reversed.
Sources
- Ein-Gar, D., Shiv, B., & Tormala, Z. L. (2012). "When blemishing leads to blossoming: the positive effect of negative information." Journal of Consumer Research, 38(5), 846-859. doi:10.1086/660807.