No doubt, you've already seen ads for Prime Day, Amazon's two-day shopping event for Prime members only, July 15 and 16. Perhaps you even caught the live-streamed Taylor Swift concert that kicked off the festivities. And like Amazon's other 101 million Prime customers, you're probably thinking about hitting the sale for new Bose headphones, Toshiba TVs, or Instant Pots.

Don't do it. Amazon, one of the most cutthroat retailers around, has stacked the deck against you. The company has spent years trying to create an irresistible honeypot so consumers overspend in the middle of July—typically a dead season for shopping—and entrench themselves deeper into a single retailer rather than shop competitively. "If everybody had unlimited resources, who cares, but the thing is, we don't," says Kit Yarrow, psychologist and writer of Decoding the New Consumer Mind and Gen BuY. "It's pretty much a disastrous equation for the budget-minded shopper to be presented with all of these, let's call them, 'opportunities.'"