Prime Day 2021 - Review from the advertisers' point of view

Prime Day 2020 was a bit special compared to previous years due to COVID-19. Even this year, things are still not back to normal yet. Nevertheless, or maybe precisely because of that, Prime Day this year was even more successful than last year.

Members purchased more than 250 million items worldwide, saving more than on any other Prime Day before. Already in the two-week run-up to Prime Day, customers spent $1.9 billion on small business products alone - an increase of more than 100% compared to Prime Day in October 2020 (source: Amazon).

In this article, we want to draw a conclusion about this year's Prime Day, which took place on June 21 and 22.

In order to be able to measure the success of this year's Prime Day, we have analyzed the development of the most important advertising key figures with the help of the Amazon Market Index AMX500. 

It is already clear at first glance that there was a strong peak in the AMX500 index on June 21 - the first day of Prime Day. We explain how this increase occurred in the following. 


Development of advertising key figures

  • There was an increase of 63.1% in impressions and a 36.1% increase in clicks.
  • Although the click-through rate has dropped by 16.6%, the conversion rate has increased by 37.8%. People who clicked on your ad were therefore very likely to also buy your product. The increased conversion rate also suggests that many customers have already informed themselves about products before Prime Day and have specifically searched for and purchased them on Prime Day. 
  • The costs that resulted from advertising were, on average, 88.1% higher. This is mainly due to higher daily budgets as well as higher click prices (38.2% higher CPC).
  • The higher costs were rewarded with more orders and an immense increase in sales. The number of orders increased by 87.5% and the sales by a full 129.4%. The ACoS has decreased by 18%. This illustrates that sales have increased significantly more compared to costs. 

Prime Day also successful for DSP customers

In addition to PPC advertising, we also took a look at the success of DSP advertising campaigns.

DSP Überblick

Even at first glance, you can see that the RoAS is significantly higher than usual on the two days of Prime Day. However, not only the RoAS experienced a significant boost on Prime Day, but also other performance values of our DSP customers. These are the most interesting changes:

  • The revenue from DSP Ads was 213.8% higher on Prime Day.
  • This can be explained by the increase in orders (157.1% more orders)
  • RoAS increased by a full 279.2%. So on Prime Day, DSP Ads provided not only a much higher revenue, but also a higher profitability.


  • Higher daily budgets and bids are definitely worthwhile: Even if the click prices and thus also the costs are higher than usual at Prime Day, it is worthwhile to increase advertising budgets. The increasing number of orders and the growth in sales compensate for the costs by far, which can be clearly seen in the ACoS.
  • The earlier you start preparing for Prime Day, the better: It has been proven several times that it is worthwhile to start preparing a few weeks before the actual Prime Day. This gives you enough time to optimize your product listings, adjust bids and create special Prime Day deals for your products. 

  • Most popular categories: The top-selling categories worldwide for Prime Day 2021 included tools, beauty, nutrition, baby care, electronics including Amazon Devices, apparel, and household products. Especially if you sell products from one of these categories, you should invest a lot of time before and during Prime Day to achieve optimal results for your products - because it's definitely worth it.