While nearly all consumers still currently shop for the majority of their groceries in stores, retailers should expect online shopping to increase over the next five years, according to a new report from Field Agent.

Ninety-seven percent of respondents to the report said they currently shop primarily in stores for their groceries. But the survey also noted that 66% of shoppers say they expect to be buying more of the groceries online within the next five years. Furthermore, 21% say they expect to be utilizing online grocery shopping "much more," while just 6% say they expect to use it less.

Another key point in the report: retailers have a major hurdle to clear in keeping up with Walmart's online presence. A vast majority of respondents (82%) say they use Walmart for online grocery purchases. Amazon was a distant second with 35%, while Target (29%) and Kroger (23%) were the only other retailers above 16%.

Meanwhile, 17% of shoppers say they use Instacart, regardless of retailer, while 7% use both Postmates and Shipt.