Despite its massive success, Amazon Prime hasn't been able to solve one nagging problem: its heavy concentration in high-income households.
But Amazon's decision to lower prices at Whole Foods could help draw more lower- and middle-income people to its Prime program because they may feel more compelled to check out the grocery store — and ultimately find out about the many benefits of the Prime program.
"Amazon's trying to cast as wide a net as possible," R.W. Baird analyst Colin Sebastian told CNBC. "They're going to try to make more store shoppers Prime members, and then bring more Prime members into stores."
Amazon Prime, which costs $99 a year, is estimated to have signed up more than 50 million U.S. households. But a big chunk of it comes from people in the higher-income bracket, a segment that is slowly getting saturated.
A recent survey by Piper Jaffray found that 82 percent of the households making $112,000 or more a year are already Prime members, while just 67 percent of the households with income in the range of $68,000 to $112,000 a year have signed up. Those making less than $68,000 hovered around 50 percent penetration.
On Thursday, Amazon said Prime members will receive additional savings and in-store benefits once Amazon and Whole Foods' technologies are fully integrated. Jeff Wilke, CEO of Amazon Worldwide Consumer, said in a statement that the discounts will make healthy and organic food affordable to "everyone."