Amazon Prime members have begun receiving emails detailing changes to the service that will have them paying 20% more per year.

A year's subscription to Amazon Prime, which used to cost $79, will now cost $99.

Amazon Prime users were notified that the price increase will appear on their next renewal if that renewal takes place after April 17, an Amazon spokesperson told TechRadar. The yearly subscription price goes into effect March 20 for new members.

Amazon isn't exactly apologetic about the change, which it all but confirmed was happening in January, but it did offer some explanation to members.

Excuses, good excuses

"Even as fuel and transportation costs have increased, the price of Prime has remained the same for nine years," Amazon wrote its email to Prime members.

"Since 2005, the number of items eligible for unlimited free two-day shipping has grown from one million to over 20 million. We also added unlimited access to over 40,000 movies and TV episodes with Prime Instant Video and a selection of over 500,000 books to borrow from the Kindle Owners' Lending Library."

The bookseller has got a point - the value of Amazon Prime has increased immensely over the years. Nobody likes a price hike, but the company's case isn't without merit.

In an announcement on its website, Amazon noted that Amazon Student Prime memberships are also being raised to $49 a year, while Prime Fresh memberships will still cost $299 a year.