How To: 5 Things You Need to Know Before Buying Anything on Amazon.com

Amazon.com has been around for a long time now, but there are still a few things most people don't know about when it comes to buying products from them. Here's a quick roundup of tips to help you get the most out of Amazon and save some money in the process. The holidays are the busiest time of year for online shopping, but these tricks will work all year around.

#1. Get a Refund When the Price Drops

There's nothing worse than buying something and seeing it for a lower price a few days later. If it happens with an item you bought directly from Amazon.com, you can contact customer service within 7 days of the delivery and they'll refund you the difference. There isn't anything about this policy on Amazon's website,

#2. Make Them Donate Money When You Buy

There's no easier way to give a little back than to buy through Amazon Smile. When you shop using the URL smile.amazon.com, Amazon donates 0.5% of your purchase to a charity of your choice. It's all the same items and prices, with the added benefit of helping someone in need. You can find out more about the program here.

Want to make sure you never forget to use it? There are a few plugins that can help you with that. For Chrome, there's an extension called Smile Always that automatically redirects you to the Smile URL anytime you browse Amazon. Its Firefox counterpart is called Amazon Smile Redirect and also includes a Chrome version.

#3. Share Prime for Free Shipping, Video Streaming, & More

If you have an Amazon Prime account, you can extend the free two-day shipping, Kindle Owners' Lending Library, Prime Early Access, and Prime Exclusive Deals to one more person with whom you share an address.

To add someone, log in to Amazon and go to Manage Your Content and Devices. Under the Settings tab, select "Invite an Adult" under Households and Family Library. (To see how to remove someone, click here.)

Learn more about how Amazon Households works on Amazon Help. Previously, you could share free two-day shipping with up to four people total, but Amazon took that down to just one other adult (plus up to 4 children) in August 2015, though they did include more perks for that second adult.

#4. Get Your Prime Membership Extended One Month

If you have Amazon Prime and one of your packages is delivered late, you can get your Prime benefits extended by a month just by contacting customer service. If you're not a Prime member, you can't get an extension on a membership you don't have, but you can get a refund for the shipping costs you paid.

You're eligible for the extension twelve times in a year, so if another package arrives late just repeat the process. Unfortunately Amazon Student accounts aren't eligible for the extension, and the late package has to be eligible for Guaranteed Accelerated Delivery. You can read the details in Amazon's Fine Print.

#5. Qualify for Free Shipping by Adding Small Items

On Amazon, if you purchase over $35 in qualified items, you get free shipping (5-8 business days). If your order total is a few dollars short, you can add a few small household items you know you'll use (like toilet paper) to make it over the limit.

Can't find anything to add? Just buy a gift card in the amount you need to make up the difference. When it arrives, you can apply it to your account for future purchases. It may not seem like a big deal, but why pay extra for shipping when you can add things you need anyway and get it for free?

Got any other Amazon tips, tricks or hacks that aren't on the list? Let us know in the comments.