How To Use The “Jam Study” and Scarcity To Boost Your Email Conversion Rate

July 19, 2021
minute read

This post reveals an email marketing strategy we decided to implement after reading a story about selling jam…

If we reduce the amount of options someone has to click in an email campaign, will conversions increase?

An email marketing technique discovered after reading a story about jam

One day in the year 1999, two research assistants dressed as store employees invited passing customers to come try their Wilkin and Sons jams.

You may have heard of this experiment: “The jam study”.

In this experiment, consumers shopping at a grocery store encountered a tasting booth that displayed either a limited (6) or an extensive (24) selection of different flavors of jam.

Every day we are overloaded with a number of different options and make many different choices.

Some psychologists stress the importance of having many options to choose from as it is associated with a number of positive aspects of human functioning:

“a link between the provision of choice and increases in intrinsic motivation, perceived control, task performance, and life satisfaction … even purely illusory perceptions of choice will have powerful effects” (Iyengar & Lepper, 2000, p. 995).

On the other hand, psychologists argue that too many options to choose from (choice overload) can have negative psychological consequences, such as:

“a decrease in the motivation to choose, to commit to a choice, or to make any choice at all; a decrease in preference strength and satisfaction with the chosen option; and an increase in negative emotions, including disappointment and regret.” (Scheibehenne et al., 2010, p. 409).

So what happened with our shoppers looking at different types of jam?

Of the 242 customers who passed the extensive selection display of jams, 60% (145) actually stopped at the booth. In contrast, of the 260 customers who passed the limited-selection display of jams, only 40% (104) stopped. (Source)

On the surface, it looks as tho the extensive selection (24 jams to choose from) is going to generate more sales because it has attracted more shoppers.

However these were the results:

jam study results


More choices (24 jams) attracted more shoppers (60%), but only converted 3% (4 shoppers) into buyers.

Less choices (6 jams) attracted less shoppers (40%), but converted 30% (31 shoppers) into buyers.

“Thus, consumers initially exposed to limited choices proved considerably more likely to purchase the product than consumers who had initially encountered a much larger set of options.” (Source)

This is why only looking at open rates and click-through rates in your email campaigns can be deceiving. While a high open rate looks good, it doesn’t always equal more customers, revenue and profit.

In the “Jam study”, if they were only looking at how many people the stand attracted, they would have been fooled into thinking that providing more choices of jam was better.

A more effective email marketing plan: Offer less

Armed with the “jam study” in mind, and after reading another post about this experiment, Rejoiner’s A/B testing team wanted to test this research in the email marketing field to see its effect on a campaign’s conversion rate.

The team decided to run an experiment on a clients 2-step win back email campaign, which is triggered to send to customers who haven’t made a purchase in 51 days.

(Why you should be sending win back email campaigns and how to make them convert is covered in detail in this post)

Email 1 of the original win back campaign contained:

  • Copy explaining that we hadn’t seen the customer in a while
  • A 10% off offer
  • Footer navigation with 12 additional links back to specific parts of the supplement company’s website

See the creative below:


The idea here was to make it easy for the reader to find the specific goal they were looking to achieve (Maximum Muscle & Strength (or) Strong, Fit & Toned, etc) which makes sense if you think about it logically.

The campaign gives more options (12 additional links) to choose from.

But will that help the reader or does it just result in choice overload?

That’s what we wanted to find out…

The Test: Removing The Footer Navigation To Reduce The Amount of Options To Choose From

We wanted to reduce the amount of options a reader had and bring the focus to the orange ‘SHOP NOW’ call to action button.


Would removing the footer navigation (with the 12 additional links) make it easier for the reader to make a decision and show similar results to the “jam study”?

Let’s take a look at the results of the first emails:

The Control – contains 12 links in the footer navigation.

The Variant – contains no footer navigation.

win back email experiment email 1

The conversion rates are:

  • 2.52% for the Control.
  • 3.01% for the Variant.

There is a 19.48% lift in conversions for the variant, however we always wait for 100 conversions on each email before drawing any conclusions if the confidence level is less than 95%. You’ll notice here it’s only at 85.48%.

It’s hinting at providing similar results to the ‘jam study’.

However, it’s the results of the second email which really caught my attention.

Firstly, here’s the creative of the second control email (which is sent 4 days later):


And here’s what the second variant emails looks like when we remove the footer navigation:


As you may notice, the second group of emails include an element of scarcity by letting the reader know that:

  1. Time is running out.
  2. That the discount ends today.

We found that with the combination of removing the footer navigation (reducing options to choose from) and adding in an element of scarcity, that this is when our results ‘took off’.

How We Achieved Email Marketing Success: Removed Footer Navigation + Added Scarcity

win back email experiment results email 2

As you can see above, the combination of removing the footer navigation and adding in scarcity has provided a 63.46% lift in conversions with a 99.76% confidence level.

It’s been well documented that true scarcity can help increase conversions rates and revenue. The insights we took from this experiment is that reducing the amount of choices someone has and giving them a deadline before their offer runs out allows us to improve the result that we’re optimizing for, in this case it’s the conversion rate to sale.


  • The ‘jam study’ showed that:
  • By offering more choices (24 jams) more shoppers (60%) would be attracted to the stand, but only 3% would buy.
  • By offering less choices (6 jams) less shoppers (40%) would stop by the stand, but 30% would make a purchase.
  • By giving people less options to choose from (in this case, removing the footer navigation which contained 12 additional links) there was a small lift in conversions.
  • When we provided less options and added an element of scarcity, this is when conversions took off, providing a 63.46% lift in conversions.

What To Do Next

  1. Take the learnings from this post and test them in your company’s email marketing campaigns. As stated, this test was executed on a win back email campaign for a supplement company, you may see different results with different types of campaigns and if you’re in a different industry.
  2. Schedule a free strategy session

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Rejoiner team works with 350+ online retail & eCommerce companies like Hydroflask, Titleist, GUESS, and Big Chill. We help them grow faster using lifecycle email.

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