Can anyone help on these questions? I need something details or even with examples. What do people and/or companies use Facebook for?

Can anyone help on these questions?

I need something details or even with examples.

What do people and/or companies use Facebook for?

Can you share different cultural usage in Europe, the Middle East, China and South America? 

Are there any limitations in certain countries? What may be the cultural differences and why?

You may want to use Hofstede's cultural dimensions to analyze the countries cultural differences.