Amazon’s popular subscription service, Prime, has doubled in size over the past two years to 80 million members, according to new data released Tuesday by research firm Consumer Intelligence Research Partners.
That number is up 38% from last year, when the firm estimated that Amazon had 58 million Prime members.
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The findings show yet again how Amazon Prime has become one of the central pillars of Amazon’s e-commerce and streaming businesses. For $99 annually, Amazon Prime members can access and stream digital movies, TV shows, podcasts, and Amazon’s original productions in addition to getting free two-day shipping and one-hour delivery on certain orders.
Prime is intended to encourage shoppers to spend more money with Amazon on products like toilet paper, laundry detergent, coffee, and toys. Members are also less likely to shop with Amazon’s rivals.
For example, Prime members spend an average of $1,300 annually with Amazon, compared to about $700 for non-members, according to CIRP.
Last year, Amazon gave customers the option of paying $10.99 monthly for Prime, a slight premium over the annual membership. Just over a quarter of all Amazon Prime members now do so, according to the report.
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Amazon recently started provide details about the revenue it collects from Prime subscriptions. During 2016, it made $6.4 billion from those subscriptions, up from $4.47 billion in 2015.
It’s just a fraction of the company’s $136 billion in overall sales. However, the money from subscriptions is beside the point compared to the overall benefits to Amazon’s business.