The acquisition, which has not yet received approval from the shareholders of Whole Foods Market, adds a 27% premium to Thursday's closing value of its stock.
The deal represents a dramatic turn in strategy for Amazon, which has offered food delivery through its AmazonFresh service for a decade, but has not made a major dent in the $700bn grocery market. The same goes for Shipt, an Alabama-based grocery delivery service that's also a Whole Foods partner.
There's also the "grocerant" trend - a blending of grocery stores and restaurants. "Barclays put an upside value on Whole Foods of $57, which has probably encouraged investors to bet on at least one more raise of the paddle". But Whole Foods has lost market share to rivals Kroger Co, Wal-Mart Stores Inc, Costco Wholesale Corp and others that have elbowed into the natural and organic segment Whole Foods pioneered. Sprouts Farmers Market, which gets roughly 60% of its sales selling fresh produce, declined 6.3 percent.
Grocery shopping - you either love it or hate it.
"They really want to be communicated with the way they want to be communicated with", Hauptman said.
Mackey will remain as CEO of Whole Foods after the deal closes, and the headquarters of the grocery supermarket chain, now under pressure from fierce competitions, will stay in Austin.
"This is an quake rattling through the grocery sector as well as the retail world", said Mark Hamrick, senior economic analyst for Bankrate.com. But she would never buy food online, she said.
Amazon has turned malls upside down, but had left grocery stores unscathed.
But Whole Foods has seen its sales slump and in February said it no longer saw the potential for expanding its flagship chain to 1,200 locations, up from about 460 in the United States, Canada and the United Kingdom.
Several workers expressed relief and happiness about the planned sale, which came as Whole Foods faced pressure from hedge fund investor Jana Partners to improve results.
The Whole Food purchase price topped $13.7 billion dollars in cash.
"They (Amazon) always try to offer the best price, which is good for the customer, but not good for the brand", Motkin said. Shoppers skip the checkout line, and their Amazon accounts get automatically charged.
"Sadly, the hard-working men and women who work at Whole Foods now face an uncertain future because the Amazon model for grocery stores ultimately leads to fewer jobs, worse benefits, and more automation", Perrone said.
Both companies said there will be no layoffs, but did not respond to other questions about Amazon's plans for Whole Foods.
Belpointe Chief Strategist David Nelson told CNBC that the acquisition of Whole Foods will give Amazon.com, Inc. And the key measure that retailers look at to gauge their health, revenue at stores open more than a year, has fallen for seven quarters in a row.
Meanwhile, in a letter to its customers, Whole Foods Market, Inc.