Melissa Corbin, a 54-year-old freelance writer in Clarksville, Tennessee, landed a plum assignment last year to cover the Italian Michelin Awards in Parma, Italy. To dress the part, she turned to the world’s largest online retailer: Amazon.

Sure enough, Corbin found an appealing cocktail dress at an affordable price. However, when the outfit arrived about a month after she placed the order, the gown was a far cry from the photos in the listing. 

“I swear it looked like a tube of sheer polyester yuck,” Corbin says.

To make matters worse, the Amazon vendor that sold the dress reneged on its guaranteed satisfaction policy. Instead, it offered Corbin only a 10 percent refund and suggested she regift the dress to reduce the carbon footprint of mailing it back to China.

Fortunately, having paid with a credit card, she got her money back by disputing the charge with her card issuer.  

Corbin, who attended the event in a dress she later bought in person at a department store, was the victim of a bait-and-switch, a common online shopping ruse. Her experience is a cautionary tale for older consumers and provides valuable lessons for other Amazon shoppers.

“The trade-off for all that convenience is that most of the listings you see on Amazon these days are ads,” says Kevin Brasler, executive editor of Consumers’ Checkbook, a watchdog publication targeting questionable retail practices. “You can’t trust it to show you the best thing, the highest-rated thing or what most people are actually happy with.”

That means it’s up to consumers to protect themselves while shopping on Amazon. And older adults make up a large share of the retail juggernaut’s customer base, with Gen Xers and boomers representing 31 percent and 33 percent of its shoppers, according to consumer research firm Numerator.

Here are 11 slip-ups Amazon shoppers should avoid.

Shopping without a plan

Consumers of a certain age may remember what it was like staying up late, eyes glued to the Home Shopping Network or QVC, making impulse purchases. These days, Amazon shoppers might spend countless hours browsing the site’s catalog of more than 600 million products.

That kind of near-endless scrolling can lead people to overspend, says Jeff Hancock, a professor of communication at Stanford University and founding director of the Stanford Social Media Lab, which studies how psychological and social dynamics affect consumer behavior. “If people are feeling anxious or worried, that consumer scroll can make them more vulnerable to buying things they later regret,” he says.

The fix: Create a shopping list and stick to it, just like you would at the grocery store. “Try to avoid turning a purchase into a shopping spree,” says Brasler.

Scrolling while hungry

Jeff Galak, an associate professor of marketing at Carnegie Mellon University, says the adage “Don’t shop on an empty stomach” applies not only to groceries but also to online merchandise. “There’s plenty of research on the impact of low blood sugar,” he says. “It diminishes your ability to perform higher cognitive functions like determining the value of something.” 

In other words, “If you’re hungry, you make bad choices,” Galak says.

The fix: That $800 espresso machine or $400 toaster oven on Amazon? It might look less tempting if you have a snack before you start shopping.