Let's try to not be patronizing, but some artists do concentrate a lot on the music, which is totally fine of course, but step 2 (making it known) is often forgotten or, at best, badly handled.
Jess Boyer, from Blog Zimbaland, has been putting down some interesting notes about it.
Basically, these 10 points are:
Not providing basic information: your mum knows you and loves you dearly, but you need to think larger and tell the world who you are and how great your music is.
Not creating connections: whether we like it or not, being on the grid is necessary to make your music known and appreciated.
Not writing about yourselves: come on, now you can let your ego run free :)
Not replying quickly: you still need the time to think about what to answer but, please, do reply.
Not having a consistent online persona: don't scare away your public !
Being scared of other bands: on the contrary, a comparative watch can make you learn you a lot.
Not linking: interaction is vital.
Not tracking social media success: it all adds up. you need to know where it's happening for you.
Not capturing fans data: in this age of one-to-one sales, you need to know how and where to reach your fans.
the full article is here: http://www.blogzimbalam.co.uk/top-mistakes-artists-make-on-social-media/