Amazon Prime Day 2021: 3 Important Trends to Watch | Criteo

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Amazon Prime Day 2021: 3 Important Trends to Watch

See the traffic and sales spikes from Prime Day 2019 and 2020 and understand the shopping "halo effect" to expect in 2021.

Updated on February 25, 2026

Amazon Prime Day will be here before the end of Q2. After a postponed Prime Day in 2020, we expect the shopping “halo effect” to bounce back to 2019 levels and drive traffic and sales for retailers outside of Amazon.

Prime Day typically occurs in mid-July and has expanded from 24 hours to multiple days of deals just for Prime members. Over the years, a halo effect has also emerged. Many retailers promote their own deals at the same time as Prime Day to attract customers searching for deep discounts—including those who aren’t Prime members.

In 2020, despite the pandemic, Digital Commerce 360 estimates that Amazon generated more than $10 billion in gross merchandise sales during the two days of Prime Day—a 45% increase from over $7 billion in 2019.

What Will Happen on Prime Day 2021?

Prime Day is back to its summer schedule and the potential halo effect on the retail industry is uncertain. However, Prime Day is popular in the US. In a May 2021 survey, 66% of US consumers said they’re familiar with Prime Day, and 81% said it gets them in the mood to shop.

Trend #1: The Prime Day 2021 halo effect will more closely resemble 2019.

The Prime Day halo effect is defined as the increase in traffic and sales that retailers outside of Amazon enjoy due to the event. Our data shows that there is a clear increase in traffic and sales for our retailer partners around Prime Day.

Traffic increased 12% on the first day of Prime Day in 2019, and sales increased 24% on the same day. In contrast, Prime Day 2020 saw lower growth rates with traffic only peaking at 5% above average.

Trend #2: Prime Day promotions will become table stakes for retailers.

Participating retailers saw a significant sales increase during Prime Day compared to those who did not run promotions. For instance, participating retailers had a 71% average increase in sales on the first day of Prime Day 2019.

Trend #3: Tech will be big this year, but sales in every category will spike.

While tech deals are typically popular on Prime Day, consumers also show high interest in various categories, including:

How to Take Action Ahead of Prime Day

To benefit from the expected halo effect, run special discounts targeting three types of audiences in the week surrounding the event.

Audience #1: Retailer Website Audiences

Run retail media campaigns to reach consumers actively browsing retail websites when traffic is higher than usual.

Audience #2: Commerce Audiences

Engage potential customers through targeted advertising based on their shopping habits and preferences.

Audience #3: Online & In-Store Shoppers

Engage audiences of recent website visitors and in-store shoppers to drive sales and guide them toward in-store visits during Prime Day.

Bonus: Contextual Targeting

Contextual targeting can be utilized as a sustainable advertising solution around Prime Day to reach consumers likely to buy.

Ready to build a campaign? Contact your Criteo account strategist or click here to talk to an expert today.

1Criteo Consumer Sentiment Index, US, May 2021, n=483

2Criteo Consumer Sentiment Index, UK, May 2021, n=367

3Criteo Consumer Sentiment Index, Singapore, May 2021, n=132

4Criteo Consumer Sentiment Index, Australia, May 2021, n=128

Tricia Carr is a writer and editor obsessed with learning new things.