• by Sarah Mahoney  @mahoney_sarah, June 21, 2011

Nielsen and MyWebGrocer are forming a new partnership to track the fast-growing area of online grocery sales. While online grocery shopping accounts for just 2% of total U.S. consumer packaged goods sales, it is expected to explode in the next few years, growing from $12 billion now to $25 billion by 2014.

That increase "is because we're seeing big changes in how consumers connect to retailers, between the growth of mobile and the growth of iPads," John Burbank, president, Strategic Initiatives, Nielsen, tells Marketing Daily. "Consumers can now shop anywhere they might be, at any given moment. That's a big change from 10 years ago, when they had to be at their home computers." He adds that consumer acceptance of online grocery shopping is considerably higher in Europe.

In April, Walmart announced that it was testing "Walmart To Go" in San Jose, which allows customers to shop online, then have products, including such perishables as produce, meat and frozen items, delivered to their home. And in recent weeks, Amazon has said it is further experimenting with Amazon Fresh, another home delivery concept, in Seattle.

As the online market grows, Burbank says, traditional stores, such as Walmart and Tesco, will continue to evolve their online offerings, competing with the likes of FreshDirect, Peapod and Alice.com. "Conventional retailers will continue to innovate, as more and more non-brick and mortar stores invade the space," he says.

But the distinction between online and instore shopping continues to get fuzzier, as consumers switch channels more fluidly. Nielsen reports that 25% of U.S. CPG purchases are researched online, including retailer weekly ads, and that 97% of the time, the researched product is eventually purchased.

Data from the new strategic alliance will be available later this summer, he says, and will include MyWebGrocer's e-commerce sales information from 60 U.S. supermarket retailers, measuring 30% of online supermarket sales in the U.S.