The library of free content Prime viewers can see isn't quite there compared to dedicated streaming services like Netflix though. Plus, you will have to pay to rent or buy newer titles.
The real problem with viewing Prime Instant Video is that it doesn't work with every device out there. There's an Amazon Instant Video app for most Apple iDevices, media apps for the Xbox and PS3 as well as the Roku, but surprisingly - or not - there's no support for most Android devices other than Kindle Fires.
Free books! (If you have a Kindle)
The free library of borrowing books that Kindle or Kindle Fire owners can access with Prime is similar to Instant Streaming in that it has big titles like the Harry Potter series, but it's mostly filled with older or indie titles. So you might be hard pressed to find something you actually want to read.
What's even more limiting is the Lending Library is only accessible through a Kindle device; which means borrowing books won't work if you just have the Kindle app on any old device you want.
Is Amazon Prime right for me?
Amazon Prime's most attractive bonus is still the loads you could save on express shipping, which in turn makes impulsive buying online an easy trap to fall into. If you're strictly looking for something to deliver digital entertainment to your living room though, you would probably be better served with a streaming service like Netflix.
Kindle owners, meanwhile, get the full breadth of advantages that Amazon Prime provides, complete with mobile access to the Instant Video streaming and free monthly books.
Putting it all together, the combination of delivery, unlimited streaming and free Kindle books makes Amazon Prime a tantalizing buffet of physical and digital stuff all packed into a single subscription. But ultimately, it's all up to you to decide if it's really worth your yearly £79.