Analysts' reactions to Prime Day, Amazon's (AMZN  ) annual 48 hour digital sales discount event that first started in 2015, have not been unanimously positive, with some pointing toward signs that year's event did not result in as much growth as last year's event.

For starters, several have noted the fact that Amazon's overview and coverage of this year's event was much more limited than usual, lacking the sales superlatives typically used by Amazon when recapping the event and noticeably excluding data on third-party sellers that was provided for Prime Day 2020.

Per Amazon's Prime Day 2021 press release (headlined by a statement on the boon that the event provides for small and medium sized businesses), Amazon's customers spent $1.9 billion on small business products in the two-weeks leading up to Prime Day as part of its Spend $10, Get $10 promotion, a 100% increase from the same promotion during Prime Day 2020.

While any signs that small businesses are prospering from Amazon's online marketplace are encouraging, this is not as substantial as Amazon's revelation in their 2020 press release that third-party sellers generated some $3.5 billion in sales during Prime Day 2020 (a 60% increase from the year prior). Further absent from the 2021 press release is any mention of member savings in dollar terms - per the 2020 press release, Prime members saved more than $1.4 billion during Prime Day 2020.

Amazon disclosed that 250 million items were sold during the 2021 event, an estimated 20% year-over-year growth rate from the 175 million items sold during Prime Day 2019, per Bank of America analysts, who suggest that this likely represents limited growth vs Prime Day 2020--for which Amazon did not provide items sold figures in their official press release). They attribute this suggested soft growth to the short period of time since Prime Day 2020 (which was delayed till October due to the pandemic), the lack of additional participating countries (plus the fact that Canada and India did not participate due to the pandemic), and the lack of new disclosures with regard to the marketing of the event.

Amazon does not provide data for total Prime Day sales in dollar terms, but BofA analysts estimate that gross merchandise volume for Prime Day 2021 totaled $9.55 billion, a 7% increase from 2020. This 7% increase is small relative to the 54% growth in gross merchandise volume that they suggest occurred between Prime Day 2019 and Prime Day 2020. These estimates for Amazon's gross merchandise volume growth are consistent with estimates for the growth of total U.S. online retail sales during the 48 hour event - according to Adobe, total online retail sales in the U.S. during Prime Day 2021 were 6.1% higher than those of Prime Day 2020.

Other industry analysts are not as concerned as the BofA analysts referenced above - Piper Sandler analysts have noted that they believe Prime Day results were on par with their estimates and Baird analysts have suggested that Salesforce data showing that Prime Day deals and other competing deals slumped 1% compared to the October 2020 Prime Day was expected and in part influenced by the amount of store closures during Prime Day 2020 relative to this year as well as holiday shopping demand that the normally scheduled Prime Day does not capture.

Further, Adobe notes that both larger retailers (those generating more than $1 billion in annual revenue) and smaller retailers (those generating less than $10 million in annual revenue) benefitted from the event, with reported 29% and 21% increases in e-commerce sales for Prime Day 2021, respectively, compared to a normal June day.

Note that going into Prime Day 2021, several analysts were worried that current supply chain disruptions would handicap third-party sellers' ability to effectively meet demand and capitalize upon the event.