This article is more than 2 years old.

July 9, 2017 This article is more than 2 years old.

Amazon kicks off its third annual Prime Day sale on the evening of Monday, July 10, with deals available to subscribers of its Prime annual membership in 13 countries.

Amazon has successfully used the incentive of Prime Day access in the past to boost the ranks of Prime members, who spend more and stick around longer, making them Amazon’s most valuable customers.

Here’s how to think about Prime Day 2017, based on earlier years and what Amazon has announced:

There will be some good deals

BestBlackFriday.com analyzed last year’s Prime Day prices and found that 77% were lower than on the Black Friday shopping holiday in the fall, with 13% of the prices equal on both days.

Relatively few Prime Day deals are truly amazing

Gadget review site the Wirecutter last year recommended only 64 Prime Day deals of the nearly 8,000 it scanned. You can paste Amazon product page urls into the CamelCamelCamel site to see how good the price is for a specific item compared to what Amazon has historically charged.

Amazon’s own devices will be on sale

If last year is any guide, Amazon will offer significant discounts on its own devices, such as Fire tablets, Kindle e-readers, Fire digital-TV streaming sticks, and Echo smart speakers. The Echo was just $129.99 last year on Prime Day, compared to its usual $179.99. Amazon sold “hundreds of thousands” of Kindles on Prime Day last year. The Fire TV Stick was the best-selling Amazon device.

Amazon has promised deals on television sets this year

The company said there will be “amazing TV deals, with a variety of great brands including the all new Element 4K Ultra HD Smart LED TV.” Amazon said it “is planning one of its largest total volume TV deals in history with a record level of inventory but once again, the TV deals will likely sell out.” It sold 90,000 TVs on Prime Day 2016.

Ordering via an Amazon device will activate additional savings

Amazon is giving shoppers ordering using its voice-activated service on devices such as the Echo extra discounts and providing them with access to some Prime Day sales two hours before everyone else.

Amazon has already started releasing some deals

The online retailer is offering discounts on subscriptions for ebooks, audio books, and music ahead of Prime Day. Prime Day sales on La Croix sparkling water, Coppertone sunscreen, beer and wine, and other products have already started under Amazon’s Prime Now two-hour delivery program, in cities where it’s available.

From within Amazon’s free app, you can view deals 24 hours before they go live, and sign up to be alerted when a sale you’re interested in starts.

Prime Day is longer than a day

The sales start at 9pm ET on Monday, July 10, and run through 3am ET on July 12, making the sale 30 hours long.

You can get help finding the best deals once Prime Day kicks off

The Wirecutter is posting the best deals it finds on Twitter and its deals page. New York magazine is providing its own list.

Don’t forget to raise funds for charities while you shop

If you shop through smile.amazon.com and designate a charity, Amazon will give it a percentage of the value of your purchases.

You’d probably be happier if you ignore Prime Day and plan your next vacation instead

Research consistently shows that doing things makes people happier than having things. Spending money on, say, a plane ticket for a vacation is more satisfying in the long run than purchasing a new television for the same price.