Amazon Prime members are way more likely to shop on only Amazon by Benjamin Snyder @FortuneMagazine April 7, 2015, 11:59 AM EDT E-mail Tweet Facebook Google Plus Linkedin Share icons Amazon Prime members are much more likely to do their online shopping exclusively on Amazon, according to a new study. Research consultancy group Millward Brown Digital reported that less than 1% of Prime members—who receive two-day shipping, video and music streaming as part of the $99-a-year membership—even consider shopping on other retail sites, according to Forbes. Meanwhile, a sans-Prime Amazon shopper is eight times as likely than a Prime member to switch between Amazon and Target.com. A Consumer Intelligence Research Partners survey estimates that Amazon has about 40 million Prime members. That figure is reportedly up from about 10 million in 2013. In January, Amazon reported fourth-quarter earnings of $214 million on $29.3 billion in sales, beating analysts’ expectations.