Amazon (NASDAQ:AMZN) Prime is a hit: By some estimates, the service -- which combines a number of physical and digital perks -- boasts as many as 60 million subscribers.

Prime members are valuable to Amazon -- on average, they spend nearly three-times as much as non-members -- and Prime perks can be quite valuable to subscribers.

Semitrailer with Amazon Prime logo on it

Image source: Getty Images.

While Amazon Prime is headlined by the popular free two-day shipping feature, there's much more to Prime than that. In recent months, Amazon has added a number of new features that make its membership program all the more enticing. Below are five features members should be taking advantage of.

1. Exclusive video content
Besides free two-day shipping, Amazon's Netflix-like video service may be the second-most popular Prime perk. Amazon originally launched Prime Video in 2011, but has bolstered the service in recent months with a catalog of exclusive shows.

There's reason to believe that many Prime subscribers aren't taking advantage of their video subscription: Somewhat surprisingly, only 40% of Amazon Prime subscribers have watched an episode of its critically acclaimed original series, Transparent, according to a recent survey from Consumer Intelligence Research Partners.

Although it isn't as ubiquitous as Netflix, there are many ways to access Amazon Prime Video.

PC users can stream shows directly through the browser; those on mobile devices can download the app. Prime Instant Video comes preloaded on Amazon's own Fire Phone and Fire tablets, but fans of Apple products and other Android devices can get it, too. Amazon offers a Prime Instant Video app through the iTunes app store, but owners of Android devices have to do a bit more work. Unfortunately, the Prime Video app is not directly accessible through the Google Play app store, but can be downloaded by visiting in the mobile browser.

For those looking to watch Prime Instant Video on the TV, there are many options. Various smart TV models from Samsung, LG, Vizio, and Sony come with Prime Video apps, but not everyone has a smart TV. A better option may be to access Prime Video through a set-top box or game console. Amazon itself offers the Fire TV and Fire TV Stick, but Roku products will also work. Apple TV owners can watch Prime Video, but they will need to beam the content from a paired iPhone or iPad using AirPlay. Meanwhile, all major video game consoles, including the Wii, Wii U, Xbox 360, Xbox One, PlayStation 3 and PlayStation 4 offer Prime Video apps.

2. Free photo storage
Amazon Prime members can store an unlimited number of photos in the cloud -- a great perk for iPhone users, as Apple limits the amount of free iCloud storage space to just 5GB.

Amazon Prime members can upload photos from their PC using Amazon's website, or download the Amazon Photos app through the iTunes app store or on Google Play. Prime members can choose to backup photos individually, or set the app to upload photos automatically over Wi-Fi.

3. Listen to over one million of songs for free
Prime members also get access to Amazon Prime Music -- a service that might be best described as a low-end Spotify.

For die-hard music fanatics, it won't replace Spotify (or other, similar streaming services), as it offers far fewer songs (just over 1 million, compared to Spotify's 30 million plus), but it may be a cheaper alternative. By downloading the Amazon Music App or visiting the website, Prime members can stream songs on demand, commercial free.

4. Borrow Kindle books
Prime membership confers access to the Kindle Lending Library. Unfortunately, this is one perk that requires Amazon-made hardware: Kindle books can only be lent to Kindle devices (e-readers or the various Fire tablets).

But if you do have a Kindle, you can borrow books from a collection of over 800,000. As long as you remain a Prime subscriber, you can keep the book, but you can only borrow one at a time.

5. Restock the pantry
Lastly, Amazon Prime members get access to Amazon Prime Pantry -- a service designed to facilitate the purchase of household goods (paper towels, cotton swabs, toilet paper) and long-lasting groceries (soda, cereal, soup).

Here's how it works: You visit the Amazon Prime Pantry website, and click on a given item. Amazon will tell you the price of that item, and what percentage of a Pantry box it fills up (for example, a 12-pack of Coca-Cola costs $4.58 and fills up 23.2% of a Pantry box). Each Pantry box costs $6 to ship.

If you're a Costco or Sam's Club member, it's not a great deal. But urban dwellers with limited super market access, or those who simply don't have time to go to the store, may find it particularly useful.