Can Amazon change the way you buy groceries? That's what they are trying to do. The online retailer wants to take a big bite out of the $800 billion-dollar grocery market.

On Amazon Prime Day, July 16th Whole Foods Market will offer discounts to try and get shoppers to switch from brick and mortar stores to on-line shopping.

Amazon acquired Whole Foods last August for $13.7 billion. Prime members are being offered $10.00 to shop online during Prime Day if they spend at least $10.00 on groceries at a Whole Foods store. Is it worth it? Loris Silverman in Clark Howard's Consumer Action Center says, " if you are an existing customer of Whole Foods of course you'll get a discount and it's worth it, but if you shop someplace else you should probably continue shopping there because you're not going to get a bigger discount shopping at Whole Foods, even with the Amazon Specials."

"Online grocery shopping is growing, especially in larger cities like New York”, says Silverman. According to the Food Marketing Institute and Nielsen, by 2022 it's expected that seventy percent of households will be ordering groceries online.