Low prices, free shipping, and convenience make Amazon the go-to retailer for many online shoppers. No matter what you want, you can find it there (and usually at a great price). But you’re probably missing out on some great deals. Here are five mistakes you might be making on Amazon–and how you can fix them to save even more money.

You don’t time your purchases right

If you’ve ever left an item in your Amazon cart for more than a day, you’ve probably noticed the price go up and down. That’s because Amazon’s prices fluctuate all the time. To get the best deals, use the Amazon app–they’ll send you a notification when the cost of an item in your cart has changed.

You don’t comparison shop

Sure, Amazon offers great prices–but that doesn’t mean they always have the best price. When other retailers have sales or special promotions, there’s a good chance they’ll have the better deal. Use a plugin like Wikibuy to let you know when an item is priced differently somewhere else and be sure you’re getting the most bang for your buck.

You’re not signed up for recurring deliveries

Do you use Amazon to buy your vitamins every month? Get the kids’ school snacks? Stock up on other essentials? If you do, and you’re not signed up for recurring deliveries, you’re missing out. Thousands of products qualify for this service where they’ll automatically send your order out at given intervals, and it often saves you a lot of money.

You don’t have Prime

Amazon Prime costs $119 a year, but if you’re a frequent shopper, it’s well worth it. Benefits aren’t limited to free two-day shipping: they also include access to Prime Video, Prime Music, discounts at Whole Foods, deals on Alexa, and much more. They’re even going to offer free restaurant delivery to Prime members soon!

You always opt for free shipping

If you’re a Prime member and don’t need your order right away, it pays to use no-rush shipping. Amazon rewards the use of slower shipping methods with everything from an immediate discount to promotional rewards that can be used toward Prime Pantry, Prime Video, the Kindle Store, and more.