Need more evidence that Amazon.com Inc. (AMZN) is killing it when it comes to American shoppers? According to a new analysis, the Seattle-based e-commerce giant accounted for about 5% of all retail spending in the U.S. last year.

Bloomberg Intelligence crunched the numbers and found Amazon sold around $300 billion in products last year, with two-thirds of the sales coming from the U.S. alone. That would give Amazon 5% of U.S. retail spending, excluding purchases of vehicles and in restaurants and bars. While 5% market share may seem huge, it's less impressive when compared to Walmart Inc. (WMT) which Bloomberg found had sales of $381 billion in its last fiscal year. That amounts to 10% of all Americans’ spending on retail excluding those cars, restaurants and watering holes. (See also: 2 Trillion-Dollar Markets Amazon Will Disrupt.)

Amazon Dominates Online

While Amazon is still behind Walmart in retail spending, it is dominating online and its might is only expected to grow. Bloomberg pointed to data from research firm eMarketer which expects Amazon’s market share in online shopping to grow to 49% this year, up from 43.5% last year. eBay Inc. (EBAY), which is in second place, will only have 6.6% of e-commerce sales in the U.S. this year.

Take Amazon’s Prime Day event in July for further evidence of consumers' love for its shopping platform. Despite some glitches in the early hours of this year's Prime Day shopping event, the e-commerce giant set another record with one Wall Street firm estimating it raked in $4.2 billion in sales. Based on Amazon’s disclosure that it sold more than 100 million products during the 36-hour promotion and that small- and medium-sized businesses had more than $1 billion in sales, Wedbush Securities analyst Michael Pachter came up with the $4 billion in sales figure. That's 33% higher than Amazon Prime Day 2017. (See also: Amazon Made More Than $4B on Prime Day: Wedbush.)

Amazon Thinks It’s a Small Fish In a Big Pond

While Amazon views itself as a small fish in a big pond when it comes to retail sales, its share is expected to keep on increasing. According to Bloomberg, Amazon’s revenue jumps 25% to 30% each year, which is four times the rate of growth for retail spending in the U.S. That means its market share could hit 6% this year and continue to grow in the years to come. That may embolden the anti-Amazon camp led by President Donald Trump, who has argued anti-monopoly rules should be applied to e-commerce giant. But for investors, it could mean more upside to a stock that is up more than 56% this year.