For now, Instacart is in the lead. In 2016, Instacart’s US market share more than doubled that of Fresh Direct, its closest competitor, and nearly quadrupled that of Amazon Fresh, according to an analysis of e-receipts from 4.7 million online shoppers by research firm Slice Intelligence. But that edge might not last. Instacart’s growth in orders slowed every quarter last year while Amazon Fresh’s accelerated in the second half of the year.

Gupta said multiple revenue streams have stabilized Instacart’s finances. The company’s best-known revenue line is delivery fees. Most customers pay $5.99 per two-hour delivery (and $7.99 in New York). Twenty-eight percent subscribe to Instacart Express, a $149 annual membership that includes unlimited two-hour deliveries of orders over $35. Express customers make up 50% of all orders, Gupta said. They spend an average of $450 over four to five orders a month. In other words, those customers use Instacart nearly as often as the typical American went to the supermarket in 2016, according to the Food Marketing Institute.

Instacart also earns money by taking a cut of orders at partner stores, much like Uber collects a commission on rides. (Instacart calls this “revenue sharing.”) And it has advertising deals with consumer packaged goods companies like Nestle, Unilever, and General Mills that pay to promote their products in Instacart’s app or serve coupons to its users. In some stores, Instacart also marks up item prices. A recent viral post on Reddit detailed how one Instacart user in Boston paid $154.80 to have $86.87 worth of groceries delivered from Market Basket, an increase of 78%.

Beyond that, the company is quietly working on a white-label delivery service for grocery stores, “Powered by Instacart.” Instacart has rolled out this service for Whole Foods and Schnucks, a St. Louis-based grocery chain and Midwest staple. While most Instacart orders come in through the company’s app, for Whole Foods and Schnucks, Instacart built sites where customers can place their orders directly.

The approach seems likely to help Instacart win business from chains that are worried about losing business to big-box retailers like Amazon and Walmart, but which are also wary of being overshadowed by Instacart’s brand. The Wall Street Journal reported in December that Target executives feared a partnership with Instacart was boosting the startup’s brand more than their own.

Correction: An earlier version of this article misstated that a partnership between Instacart and Target fizzled. The partnership is still in place.

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