Shopping for groceries online has a long way to go before it catches on with the vast majority of U.S. consumers.

Nine percent of U.S. adults report that their household shop online for groceries at least once a month, including 4% who do it at least weekly, according to Gallup’s annual Consumption Habits survey. By contrast, almost all Americans say someone in their family shops for groceries in person at least once a month, with 83% going at least once a week.

This pattern — highly frequent grocery shopping occurring mostly in person — highlights the possibility for enormous growth that exists in the online grocery business, the survey reported. Amazon’s purchase of Whole Foods Market recently underscored this possibility, giving rise to speculation the online giant will use the grocery chain as a launching pad to expand its online operations into the food sector, according to the…