The dark patterns websites use to get you to spend more

From low-stock messages to nagging, websites spend millions trying to figure out the best ways to encourage us to purchase.
Dark patterns take many forms: you get to a ticket purchase page and a countdown timer starts. A message tells you three other people are currently thinking about purchasing this item, and there’s only one left. Relevant information is obscured, or spelled out in a font that’s too tiny to see.
Websites spend millions trying to figure out the best ways to encourage us to spend more. They use a variety of design tools: from option placement and setting default choices to a wide range of messaging techniques.