US Amazon Prime members average 3.5 orders per month, compared with 2.2 per month for non-Prime members, according to May 2017 survey data from Cowen and Company.
Some 31% of Prime members order at least four times per month, the survey found; among non-Prime members, the comparable figure was 11%.
Prime buyers also tend to range more widely across the site, the Cowen data suggests, consistently buying from more Amazon verticals than non-Prime members do. In Q2 2017, Prime members bought from 3.4 different verticals on average, compared with 2.2 verticals for non-Prime members.
For the latest quarter, Cowen said, Prime members made up 61% of total Amazon purchasers. That proportion has shown steady growth over the past four years.
For many Prime members, the membership fee is no obstacle. Prime members are much more likely than the average consumer to live in a household with a six-figure income—28% vs. 19%, according to a March 2017 Fung Global Retail and Technology study based on the Amazon Shopper Intelligence Service, a partnership between Fung and Prosper Insights & Analytics.
Over a five-month period in 2016, market research firm GfK found that while Prime members spent an average of 12.8 hours shopping online, non-Prime members spent only 7.2 hours during the same period.