You’ve probably heard of the butterfly effect also known as chaos theory? It posits that a small trigger can have a large impact, such as a butterfly flapping its wings and causing a tornado a few weeks later.
In behavioural science, there’s a theory known as nudge. Rather than forcing people to take the action you want them to take, it suggests that the best way to influence people is to nudge them in the direction you want them to go.
In an advertising book by Max Sutherland from, I think, the 1980s, he describes the secret of effective marketing as being like a feather on a seesaw. It’s another similar idea.