I heard from a reputable source that on e-commerce websites, users find it easier to choose a product when there is an odd number of items in row, as compared to an even number.

In their experience, 3 or 5 products tested better than 4, for example. Sure enough - I can find plenty of sites with 3 or 5 products per row, but I can also find plenty of sites with an even number too.

So given that everything else remains the same:

* What actual evidence is there for an optimal number of products per
row being related to the odd/even nature?
* How/why does this affect the ease with which customers can make a
decision?

![enter image description here](https://i.stack.imgur.com/tltefl.jpg)

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