A former Amazon employee has given potential shoppers a tip to stop them from impulsively purchasing products they may not actually need.

Netflix’s latest documentary, Buy Now: The Online Shopping Conspiracy, looks at the rise of online shopping and how big companies have handled the growing demand for their products.

The film is directed by Emmy Award nominee Nic Stacey, known for her work on The World According to Jeff Goldblum. The film’s blurb reveals: “This subversive documentary reveals the tricks brands use to encourage their customers to consume – and the real impact they have on our lives and the world.”

Former Amazon employee Maren Costa, who played a central role in establishing Amazon’s first online shopping interfaces, contributed to the documentary. She is known for co-founding the group Amazon Employees for Climate Justice before her dismissal from the tech giant.

“We were constantly developing new ways to get you to buy,” she admitted. “Influence your behavior in subtle ways you never realized.”

Costa shared anecdotes about tactics used to encourage consumers to buy more, including changing the color palette of certain website elements, reports the mirror.

“We might have a certain phrase that says ‘Free shipping if you buy $25 or more.’ In one case, you made it orange at $25. In another, you make it green, and you can have nine things different ones that you test on each other,” she explained. “And there’s enough traffic to the site that you can get statistically relevant data on which version of that phrase makes the most money.”

In her commentary on consumer habits in the digital space, she gave a simple piece of advice to shoppers prone to impulse purchases online.

“If you think you need something, put it in your online shopping cart and leave it there for a month,” she advised. “And if you still want it after a month, it might be something you need.”

The documentary also introduces audiences to Anna Sacks, a “useless” TikToker with nearly half a million followers. The influencer films her travels to New York ripping through trash bags and revealing usable items thrown away by big companies, which range from luxury handbags to countless packets of candy.

Buy now: The Shopping Conspiracy is now streaming on Netflix