I use facebook for social purposes, and LinkedIn and ResearchGate for work purposes.  Just curious, why do ask?  Are you looking for the most popular ones to study or are studying breadth (which ones people use)?

Facebook and Twitter

Fb, Tw, LinkedIn, RG, Tblr and a few BBs.

In the name of ALLAH

Hi, dear friend.

I want to your purposes of use.

Thanks for your idea.

Thanks

SJVJS

In the name of ALLAH

Hi,Dear jeff sedayao. 

I want a bunch of levels of thinking people to conclude that, for the security of social networks.

Best wishing for you.

Thanks

SJVJS

Dear Jalali,

ONLY RG and to lesser time LinkedIn. 

In the name of ALLAH

Hi dear  DR seraji.

I want to receive your goal of it.

for example for fun or business

Dear Jalali,

To interact with my peers across the world to exchange my views for the sake of enlightenment. No fun, no business! 

In the name of ALLAH

Hi,Thanks DR seraji.

What's your goal of participate in social networks ?

For better communication, interaction, networking, ideas generation, exchanging ideas, learning from each others as well as knowledge contribution (for academic websites like RG, Academia, Mendeley etc.).

In the name of ALLAH

Hi,Dear professor Han Ping Fung.

I want to receive information about goal of user in social network. and use it in my paper about security of social network.

Thanks

SJVJS

Hi ,,

Know news and reading, learning and of course communicate with others

regards..

In the name of ALLAH

Hi,Dear friend.

Thanks for your idea.

Thanks

SJVJS

Stay connected to friends and family and it is also a great way to meet entirely new people.

In the name of ALLAH

Hi,thanks Dear friend.

Thanks

SJVJS