In a letter to shareholders, founder and CEO Jeff Bexos said more than five billion items had been shipped in 2017, while more members joined Prime than in any other previous year.
What began as an extension to its parcel delivery service, promising unlimited free two-day shipping, has expanded into streaming music and, significantly, video.
In March, documents obtained by Reuters revealed the US audience for video streamed on the Prime service amounts to around 26 million and has become a key tool in both member adoption and retention.
Last Prime Channels launched in the UK and Germany and the service is constantly linked with big sports acquisitions.
This week it was announced that Amazon had acquired the exclusive live rights to US Open Tennis in the UK and Ireland.