Brian T. Olsavsky
Senior Vice President and Chief Financial Officer at Amazon.com
Thank you for joining us today. Before we get to Q&A, I'd like to first thank all of our Prime members, our vendors, our 3P sellers and my Amazon colleagues, especially the worldwide ops team for a record breaking Prime Day in June. Third-party sellers are mostly comprised of small and medium-sized businesses were a big contributor to Prime Day's success. The Prime Day event was the biggest two-day period ever for these SMBs in our stores. And our 3P revenue continues to grow significantly faster than our online stores revenue. Third-party units represented 56% of our total paid units in Q2, up from a 53% mix one year ago.
Our second quarter net sales were $113 billion or at about the midpoint of our guidance range. As the year-over-year increase of 27% or 24% excluding the impact of foreign exchange and included the shift of Prime Day into Q2 this year, which added about 400 basis points to the year-over-year growth rate. Q2 of this year was a transition period for many of our customers. As the quarter progressed, people were at home less as restrictions and lockdowns eased in some of our largest geographies, including the U.S. and much of Europe. As a result, while Prime members continue to spend more with us growth in Prime member spend moderated compared to spending seen during the peak of the pandemic.
As you look at our recent revenue growth rates, I want to give you some insight into what we are seeing as there have been some noticeable intra-quarter changes in our revenue run rate. Prime Day has also been in three different quarters the past three years. So I will normalize for this impact in my growth rate comments. Also, since FX rates have bounced around all of my comments exclude foreign exchange. Here's a quick recap of our growth rates in 2020 and 2021. First, before COVID-19, we've been growing at a revenue growth rate close to 20%. 2019 full-year growth was 22% and revenue growth for the first two months of 2020 was 21%.
Once the pandemic hit and lockdowns began in March 2020, the initial growth rate jumped into the mid-30% range. Q1 of last year ended with a revenue growth rate of 27%. However, our operations network took time to step up to serve this growth in demand due to space constraints and our need to ramp up hiring quickly while prioritizing employee health and safety. By mid-May of last year, we had made good progress to open up more capacity by adding hundreds of thousands of employees. This allowed our revenue growth rate to jump to the 35% to 40% range and remained at that level through Q1 of this year when we had 41% growth.
In Q2 of this year, we began to comp this high sales period from last year and the year-over-year revenue growth rate has narrowed. It has also narrowed as vaccines become more readily available in many countries and people are getting out of their homes. Since May 15, again excluding Prime Day, our year-over-year growth rate has dropped into the mid-teens. Our Q3 revenue guidance range of 10% to 16% growth reflects an expected continuation of this trend. Given all this volatility it is useful to consider the two-year compounded annual growth rate, which remains strong in the 25% to 30% range. Recall, this compares to our pre-pandemic growth rate of 21%.
This reflects the acceleration of Prime membership and Prime member purchase levels over the past 18 months. While I'm not giving forward guidance beyond Q3 of this year, we do expect this pattern of difficult year-over-year revenue comps to continue for the next few quarters. As we move forward and start to comp COVID's impact on our revenue growth we encourage you to also look at the multi-year compounded annual growth rate since the onset of the pandemic to better put this growth in perspective. Now, back to the Q2 highlights; we continue to be very pleased with the Prime member growth and engagement we're seeing.
We've been fortunate to welcome more than 50 million new members in the past 18 months and Prime member benefits usage remains high. That includes continued strong engagement in Prime's family of digital offerings like Prime Video's Original Movies. For example, Prime members help make the Tomorrow War and Tom Clancy's Without Remorse the number one streaming movies on the respective opening weekends. Amazon Advertising is innovating at a fast clip launching over 40 new features and self-service capabilities in the quarter, making it easier for sellers, companies and authors to grow their businesses by helping customers discover their brands and products.
Other revenue increased 83% year-over-year in Q2 excluding the impact of foreign exchange, driven largely by continued acceleration in our Ads business. Moving on to AWS, revenue growth accelerated across a broad range of customers. We see strong growth in enterprises, governments, educational and research institutions and our start-up and digital native customers. We recently announced new commitments and migrations from customers across a diverse set of major industries including Swisscom and Bell Canada in telecom, BMO Financial Group and Bancolombia in financial services and Ferrari in automotive.
AWS customers recognize that the move to the cloud is very positive for their businesses in the medium and long-term. Disruptive economic events like COVID have caused many people to step back and think about how they want to change strategically. And many have come to the conclusion that they do not want to own and run their own data centers. They say they can save money and gain agility and innovation by moving to AWS. I'll finish up with some comments on our ongoing investments in operations. As we think about the pull forward in demand we've seen these past 18 months, it has required and will continue to require a significant amount of investment in our fulfillment network.
Our teams have done a remarkable job stepping up to serve customers and support our vendors and sellers and we have worked hard to increase capacity at a rapid rate. For the trailing 12 months ended Q2, capex and equipment finance leases increased 74% versus the prior trailing 12-month period. And as usual, most of our 2021 spend and building openings are planned in the second half of this year. This is all part of a multi-year investment cycle for us. Unit volumes while obviously growing at lower rates of last year's large comp continue to remain high and we see strong demand for FBA and third-party sellers. So there's more work to do, including additional build-outs of our FCs as well as our middle mile and last mile capabilities to support our fast improving delivery offers for customers.
I encourage you to read the business highlights in our press release. It's a diverse collection of efforts, supported by many thousands of customer-focused Amazon employees, from Amazon Pharmacy to Business Prime to AWS' plans to add seven new regions to NFL Thursday Night Football starting next year to the Black Business Accelerator program to Alexa's collaboration with Ford Motor Company. We remain heads down focused on driving a better customer experience. We believe putting customers first is the only reliable way to create lasting value for our shareholders.
With that, let's move on to Q&A.
