1. Reciprocity:

We feel obliged to repay people who have done us a favor.

Example: When waiters gift free mints with the bill, tips go up by 14%.

2. Mimetic Desire:

People have a desire to be more like their role models and copy them.

This is why athletes like LeBron and Ronaldo are paid so much to wear Nikes:

People want to wear what their role models are wearing.

h/t @lukeburgis

3. Risk Aversion

We often hesitate to purchase things because we hate the thought of buying something and regretting it later.

This is why Netflix and Spotify offer free trials - to counter our risk aversion.

4. Status-seeking:

People desire products that enhance their social standing.

And they're willing to pay a high price for it.

Example: Ferraris and Gucci bags.

5. Uncertainty Aversion:

People are more bothered by the uncertainty of a wait than the duration.

This is why you see countdown clocks at traffic signals.

It's also why your Uber Eats app gives you an estimated time for your food to arrive.

6. Anchoring:

People are more willing to pay a higher price if they see a big number first.

It's how sales work:

Original price: $50 Sale price: $10

$10 looks like a steal compared to $50.

7. Scarcity:

Also known as FOMO.

People feel an urge to buy something if they feel it won't be available tomorrow.

You've probably heard the following phrase many times:

"Buy now while sales last."

8. Halo Effect:

Our overall impression of an offer is usually influenced by one positive attribute, like physical attractiveness.

This is why so many ads feature tall and attractive people.

9. Social Proof:

It's much easier for us to buy something if we see other people buying it too.

This is why Amazon shows you the number of reviews next to the item:

If thousands of other people bought and liked this item, so will you.

10. Authority

When people don't have all the information, they'll use the recommendation of an expert to make up their minds.

This is why so many toothpaste commercials feature dentists.

Bonus: Social Belonging.

Humans have a need for social belonging.

And sometimes we use products as a means to find our social circles.

Think of the tribal bond that so many Tesla drivers have.

Recap:

1. Reciprocity
2. Mimetic desire
3. Risk Aversion
4. Status-seeking
5. Uncertainty Aversion
6. Anchoring
7. Scarcity
8. Halo Effect
9. Social Proof
10. Authority
11. Social Belonging