As psychologists say, a human rather frequently is leaded by "unconscious brain" and cognitive baises while taking decisions.
Almost all Web sites have target behaviors. How do they get us to
engage in the target behavior? How do they get us to buy, register,
donate, and click? What makes us click?
To get us to click, they have to persuade us. But don’t make the
mistake of thinking that the best way to persuade us is to make a
logical presentation. Most behavior and decision-making isn’t
conscious. That means that they will have to engage the mid brain and
the old brain, in addition to the new brain.
from Neuro Web Design by S. Weinschenk
Cognitive biases like these play a significant role in the way we make
decisions so it’s not surprising that people are now examining these
biases to see how to exploit them in the design of web sites. I’m
going to use the term ‘persuasion architects’ to describe designers
who knowingly use these techniques to influence the behaviour of
from Persuasion Triggers in Web Design by D. Travis
"John Doe has sent you an invitation to play. [Accept] [Decline]"
exploits some those psy tricks:
- Reciprocity or Sense of obligation Jon Doe spent his time choosing you and sending the invitation to you. This thought makes you feel some obligation of making some actions in turn. And declining looks just unthankful and non polite. Another alternative is Accept.
- Social proof or Social validation Jon Doe plays this game, as you (probably wrongly) could infer from the message. So this could be a good game, or, at least, nothing wrong to play the game, I want follow the crowd.
- Similarity and attractiveness Jon Doe is a manager, like me (or he listens the same music, or lives same street, or just pretty guy), so I play the game, similar to him.
Some of those tricks could trigger user.