Amazon Prime tops 54 million members

Amazon Prime is a juggernaut, growing by 35 percent in 2015 to 54 million U.S. members, or one in five adult consumers in the United States, according to a new report from Consumer Intelligence Research Partners.

CIRP estimates that 47 percent of Amazon (NASDAQ:AMZN) customers were Prime members by the end of 2015.

"U.S. Amazon Prime membership increased steadily in 2015," said Josh Lowitz, partner and cofounder of CIRP. "Amazon added a net 7 million members in the holiday quarter of 2015, and 14 million members in all of 2015. Notably, the growth was spread more evenly across the year, in a large part due to the success of Amazon Prime Day on July 15."

Amazon doesn't disclose Prime membership and has only said it numbers in the "tens of millions," but the retailer did announce it added 3 million new members in a single week leading up to Christmas.

For more:
-See this USA Today article
-See this Internet Retailer story

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