A ton of customers subscribe to an Amazon Prime membership to take full advantage of the benefits that the retail company has to offer. For one, the free two-day delivery for select items appeals to most of the shoppers, which already makes the subscription worth the $99 annually.

Aside from what's on the surface, though, Amazon Prime has a lot more going on underneath. Here are some of the most notable perks that might have gone unnoticed by customers.

Unlimited Photo Storage

For photography and selfie enthusiasts, Prime Photos makes the Amazon Prime subscription a done deal. Customers can upload every single one of their photos to the retailer's servers all for free without limits or caps each month via a Web browser, Amazon Cloud Drive, Cloud Drive Photos and Amazon Appstore.

Also, customers can access their pictures on their smartphones, tablets or computers virtually anywhere because they're on cloud servers.

This offering can definitely save massive storage space, and it's just too sweet to pass up.

Music Streaming

Companies have been up and about creating the go-to music streaming service for everyone, as both Spotify and Google even started to offer three-month subscriptions of their services for just $1 recently.

Despite having a smaller repository compared to the competitors on the market, Prime Music has a pretty respectable selection that consists of more than 1 million songs, over 1,000 playlists and more than 100 stations to tune in to.

At any rate, Amazon Prime members have access to ad-free music streaming with this service.

Video Streaming

Just like the previous entry, video streaming has been on the rise, as big players such as Netflix and Hulu are getting some formidable rivals to face off with.

Prime Instant Video has a good assortment of TV shows and movies, with genres ranging from mystery and thrillers to musicals and documentaries. With "The Wire," "Mozart in the Jungle" and many others in the lineup, it's unlikely viewers won't find anything to watch.

On top of that, Amazon is also determined to produce a number of original series, where the comedy show "Transparent" was awarded two Golden Globes.

Free Two-Hour Delivery

If the two-day delivery just isn't fast enough, Prime Now provides two-hour delivery for plenty of items, which customers can take advantage of by using the Prime Now app. If two hours is still too long, Amazon offers one-hour deliveries at $7.99. However, the service currently covers only certain areas.

For the curious, the retailer uses the subway system to make quick deliveries, not drones. But Amazon is getting ready to make delivery drones in the near future, which former "Top Gear" host Jeremy Clarkson showcased, calling it Prime Air.

"We're excited about Prime Air – a future delivery system from Amazon designed to safely get packages to customers in 30 minutes or less using small unmanned aerial vehicles, also called drones. Prime Air has great potential to enhance the services we already provide to millions of customers by providing rapid parcel delivery that will also increase the overall safety and efficiency of the transportation system," Amazon says.

What's more, Amazon has a limited time offer as of right now, wherein customers stand to save $10 off their first orders by entering the code "10PRIMENOW" when checking them out.

Household And Family Library

One Amazon Prime subscription equals two adult accounts and up to four children accounts – yes, only one family member needs to sign up on Prime for everyone to share content at the Amazon Household. The two adult accounts can enjoy all the benefits of the Household membership. Meanwhile, the four children accounts can only download content approved by the household account, but they do have access to the content in the Family Library, which can hold select e-books, audiobooks, games and other apps.

More Perks

There are plenty of other perks too, ranging from Prime Pantry to Kindle features. For instance, the Kindle Owners' Lending Library lets subscribers borrow a book for free each month, choosing from a collection of over 800,000 e-books.

A lot of people on a global scale have been signing up with Amazon Prime because of the perks, and now that these hidden benefits are starting to get more exposure, even more are probably going to want a slice of the Prime pie.

"More than three million members worldwide joined Prime during the third week of December, bringing milestone growth to the membership program which offers unlimited Free Two-Day shipping, Free Same-Day Delivery, superfast free two-hour delivery via Prime Now in more than 20 metro areas, and unlimited access to tens of thousands of movies and TV episodes, including award-winning Amazon Original Series at no additional cost," Amazon said as the company reached a milestone.

It almost seems like Amazon is a jack-of-all-trades at this point, but nevertheless, the convenience and access to various services makes Amazon Prime one heck of a subscription.