What makes you start with STEEM?

I knew about STEEM last week when I looked for the best alt coins after seeing Bitcoin goes up so crazy.  I realized STEEM is great tool to get in touch with others about cryptocurrency. It just makes me so curious about STEEM , and how people earn $$$ just by posting, comments, etc. Where they get $$$ from? Anyway, I created the STEEM account to see how it's going. 

I am new to this, so I guess if I can answer why Bitcoin exists and have value,  then  the answer would be the same for STEEM as well.