Amazon.com (NASDAQ: AMZN) reported some stellar results in Q1, capturing how e-commerce continues to boom even as the COVID-19 pandemic begins to subside and many people are returning to work and spending more time outside of their homes. Here's a closer look at Amazon's strong first-quarter results and why they signal that these are likely still early days for e-commerce. Amazon fulfillment center. Image source: Amazon.com. Surging sales Amazon's first-quarter sales soared 44% year over year to $108.5 billion, smashing analysts' average estimate for revenue of $104.5 billion during the period. Impressively, Amazon's 44% year-over-year growth rate was equal to its growth rate in Q4. Analysts were modeling for a deceleration during Q1 -- and rightly so; not only was Amazon up against a tougher comparison in Q1 (26% revenue growth in the year-ago quarter) than it was in Q4 (21% growth in the fourth quarter of 2019) but Amazon's fourth-quarter of 2020 benefited from a Prime Day that was rescheduled from its typical summer timeframe to October. With this backdrop in mind, Amazon's ability to maintain its 44% growth rate in Q1 is particularly notable. International momentum But even Amazon's 44% growth rate for its total sales arguably understates the company's momentum. Consider that Amazon's international segment, which excludes international sales from its cloud-computing business, saw revenue grow 50% year over year on a currency-neutral basis, in line with its international growth rate in the fourth quarter of 2020. In Amazon's first-quarter earnings call, CFO Brian Olsavsky noted that its international e-commerce sales are growing at triple the rate they were before COVID-19. He suggests that there's been a significant advancement in the adoption of e-commerce internationally. Strong guidance Also putting the spotlight on Amazon's momentum is the company's rosy outlook for Q2. Management guided for sales for the quarter to be between $110 billion and $116 billion, representing 24% to 30% year-over-year growth. While this implies a deceleration from Amazon's 44% revenue growth in Q1, it's very impressive growth considering the comparison Amazon is up against; second-quarter 2020 revenue was up 40% year over year -- a huge acceleration from the 26% growth the company saw in the first quarter of 2020. Also highlighting Amazon's momentum, even the low end of its second-quarter revenue guidance range is up sequentially from Amazon's $108.5 billion of first-quarter revenue. Management doesn't always guide for such a meaningful sequential increase in Q2. For instance, consider how Amazon guided for second-quarter 2019 revenue to be between $59.5 billion and $63.5 billion after reporting first-quarter revenue of $59.7 billion. Clearly, Amazon management has great confidence in its sales momentum. While investors should naturally expect a deceleration in Amazon's growth rate in the coming quarters as the e-commerce giant laps tough comparisons, it's clear that there are still some major tailwinds working in Amazon's favor. 10 stocks we like better than AmazonWhen investing geniuses David and Tom Gardner have a stock tip, it can pay to listen. After all, the newsletter they have run for over a decade, Motley Fool Stock Advisor, has tripled the market.* David and Tom just revealed what they believe are the ten best stocks for investors to buy right now... and Amazon wasn't one of them! That's right -- they think these 10 stocks are even better buys. See the 10 stocks *Stock Advisor returns as of February 24, 2021 John Mackey, CEO of Whole Foods Market, an Amazon subsidiary, is a member of The Motley Fool's board of directors. Daniel Sparks has no position in any of the stocks mentioned. His clients may own shares of the companies mentioned. The Motley Fool owns shares of and recommends Amazon. The Motley Fool recommends the following options: long January 2022 $1920.0 calls on Amazon and short January 2022 $1940.0 calls on Amazon. The Motley Fool has a disclosure policy.Source