The findings make the segment an outlier in a web-centric consumer base, which is expected to drive online retail sales to $294 billion in 2014 and account for 9 percent of all U.S. sales, according to Forrester Research.
"Although online retail shopping is on the rise, it's not yet the go-to for grocery shoppers, now or in the near future," PwC said in the report, released Tuesday. "There's still a major obstacle to overcome: Touching the product isn't possible online."
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While this drawback to web shopping extends beyond grocery, it's been particularly troublesome for a category in which consumers like to closely examine items such as fresh produce. According to Forrester, grocery accounts for only a minuscule 2.2 percent of online sales.
But Steven Barr, PwC's U.S. retail & consumer practice leader, said there are a few factors that could give the segment a boost down the road.
"When the major retailers start to mass adopt a concept, then that certainly acts as an accelerator for changing consumer behavior," Barr said. "However, we've been tracking a number of macroeconomic 'megatrends' that we see slowly reshaping the grocery landscape. Specifically, the changing technology landscape, increased urbanization and changing demographics create the perfect recipe for online grocery retail."
Consumers' preference for traditional grocery experiences isn't limited to online. According to PwC's report, 83 percent of shoppers prefer to buy groceries at traditional grocery stores.
That's despite increasing pressure from Wal-Mart, which announced earlier this year that it's expanding its organic food offerings, and is testing grocery delivery in San Jose, California, and Denver, Colorado.
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The Denver market also allows shoppers to order their groceries online and pick up their orders in-store, without leaving their vehicles. Although Wal-Mart doesn't break out the sales for this program, spokesman Ravi Jariwala said more than 80 percent of shoppers in Denver who have used the service are repeat customers.
"More and more customers are beginning to choose pickup," Jariwala said. "We're trying to provide customers more choice."