Why people are using second life?

I went several places in SL to chat with people about why they are in Second Life.According the answers I got the people in there can be categorized into three groups.First of these is the ones using it for making new friends,broadening their social environment.The second group's purpose is just having fun and they are using it to enjoy or to have some good time.When it comes to our third and last group they are making use of Second Life for their lessons.They claim that it can provide easiness for their studies in some aspects like developing their communication skills.They say by writing frequently their skills are getting well.