Honestly, I think curiosity starts it, but timing is what makes people act faster. A bonus usually gives just enough information to make you wonder, but not enough to fully understand the value right away. I read this article about it here: https://fontcopypaste.com/news/how-gamers-build-identity-and-discipline-in-digital-spaces/. It explains pretty well how curiosity, limited-time messages, and FOMO work together. I’ve had the same experience with shopping apps too. When something says “today only,” I’m more likely to check it, even if I later decide not to use it.

Random thought, but I always find it interesting how small design choices online can change the way people behave. Even simple words, colors, or placement on a page can make something feel more important than it probably is. I usually try to slow down a bit before clicking around too much, especially when a page feels like it is pushing me to decide quickly.