Most investors realize Amazon (AMZN +3.83%) has been one of the market’s most rewarding stocks of this century so far. As the old adage goes, though, past performance is no guarantee of future results.

How might this company’s stock perform against shares of unlikely e-commerce rival Shopify (SHOP +2.32%) from here? Actually, Shopify is likely to make you richer going forward.

Don’t misunderstand. Amazon is still a solid holding. It’s got a unique challenge that will never go away, though. That’s its sheer size. With last year’s total top line of $717 billion, it’s running out of room to keep expanding its reach. Even its fast-growing (and breadwinning) cloud computing arm will eventually run out of ways and places to grow, as it also encounters competition from titans like Alphabet and Microsoft.

At the other end of the spectrum, Shopify’s smaller size is seemingly working to its advantage. Its customizable online storefronts helped facilitate the sale of $378 billion in goods and services last year, generating $11.5 billion in revenue. Those numbers were up 29% and 30%, respectively, underscoring the argument that more consumers prefer a more personalized approach to buying goods online, in contrast with Amazon’s faceless mega-mall.

And that really is the key here. Consumers are craving authenticity. Amazon can’t deliver it. Users of Shopify’s technology can.

The opportunity is enormous, too. The U.S. Census Bureau says e-commerce accounts for only about 17% of the United States’ total retail spending, while eMarketer reports only about one-fifth of that total comes from direct-to-consumer sales like the ones that Shopify helps make happen. Similar numbers apply overseas as well. That’s why Global Insight Services predicts the worldwide direct-to-consumer market is set to grow at an average annualized pace of nearly 15% through 2034, when the industry should be worth $880 billion per year.

Shopify is well positioned to capture a solid share of this expansion.