Why do You like the things that you Like?

I have a lot of time on my hands. And its times like these that make insignificant things highly noticeable.

So, what did I notice, you ask.

Facebook's widely popular feature of liking a comment/status/picture or what-have-you.
I know, I know. Its is not a remarkable observation.
But the question is :

What makes people press the 'Like' button?

People will like anything due to one of the following reasons:

1. Because it is witty/new/enjoyable etcetra and they appreciate that.

2. The emotion behind the status/picture/comment resonates within them 

3. To show support/faith

4. To publicize the event/widespread distribution of knowledge

5. To engage in battle of wits

6. They agree with you but have nothing more to add to the conversation thread

7. Because of herd mentality -  Everyone is liking it

8. To gang up against someone they do not hold in high regard

9. Because they do not like the alternative

These are all I could come up with. Do feel free to add to the above list.