Insight of the Week
January 5, 2024

Place a Focal Product in the Left Side of Bundles

If you read from left to right, you evaluate other stimuli in this pattern, including product bundles.

Bundle with leftmost item highlighted


You often see bundles of products in ecommerce.

Turns out, you prefer bundles in which the best product is toward the left (Mittelman & Andrade, 2017).

You can blame reading directionality: If you read from left to right, you evaluate other stimuli in this pattern.

"Frequently bought together" section in Amazon with focus on leftmost item

But why does it influence purchases?

You evaluate bundles by imagining yourself consuming each item. If you read from left to right, you start imagining the leftmost item. Hmm, not appealing? You feel lackluster emotions, discouraging you from evaluating the subsequent items.


  • Distinguish the Focal Item. Position isn't everything. Customers simply need to look at the best product first. Make it bigger. Make it brighter. Do something.
  • Stronger With Variety Bundles. Maybe you sell different versions of a product — size, flavor, color, etc. The effect is most prominent in this scenario. Without a default product, customers place more weight on the first item they evaluate.
  • Strongest With 2 Items. Researchers analyzed bundles of 2 items. But with 3+ items, people might follow the central fixation bias (i.e., viewing middle options first). I suspect the position effect is weaker, but we need research to validate.

Other New Studies

  • Currency Symbols - I updated my tactic on currency symbols. It had suggested removing currency symbols when possible. And sure, it might work in upscale restaurants (which was the context of the original study). But in most scenarios, you need currency symbols. However, you should modify them slightly. See the update for details.
  • Caffeine Increases the Decoy Effect - When you drink tea or coffee, you can detect relationships in products faster. If there's a similar (yet worse) product, the superior option seems even better.
  • Decoy Effects Reduce Consumption - We know that decoys influence people to choose the superior option, but these nudges also reduce the amount that people consume this chosen item.