If used correctly, these principles make you unstoppable. If used unethically, they make you a fraud.
1. Urgency
Time constraints make people act (think: limited-time discounts).
2. Scarcity
Quantity constraints drive action, too (think: only 5 items left in stock).
3. Status
People like being seen as better than others (think: sports cars, watches etc.).
4. Loss aversion
The pain of a loss exceeds the pleasure of an equivalent gain (think: don’t miss out on this 50% off sale).
5. Social proof
People like to copy others, especially if those others are credible in their eyes (think: celebrity endorsements).
6. Reciprocity
We feel uneasy when we don’t return favours (think: free samples).
7. Consistency
We’re inclined to follow through on things we’ve said and done in the past (think: this is why politicians accuse each other of lying).
8. Liking
We’re more easily convinced by people we like (think: building rapport on a sales call).
9. Anchoring
We judge prices based on other prices we’ve just seen/heard (think: lowball buy offers).
10. Emotion, Then Logic
We buy with emotion and justify with logic (think: the salesman lets you sit in the Ferrari, then tells you about the fuel economy).
NOTE: before putting these principles into practice, I recommend reading/re-reading this.