I never thought of my blog as a hobby.
The definition of the word HOBBY is:
"A subject or activity pursued for pleasure rather than for payment."That's all well and good but I think there is more to blogging than that.

Day 2 - Create by catheroo, on Flickr CC BY-NC-SA
When I hear the word hobby I think of activities like stamp collecting, knitting, painting, arts and crafts and lots of similar solitary activites. There are hobbies like tennis and golf where several people participate.
Blogging is a solitary activity but it reaches out to people.

2008 TFTTF Portland Maine Group Shot 2 by CC Chapman, on Flickr CC BY-NC-SA
So I looked up the word AVOCATION:
"An occupation or hobby that one has in addition to one's regular work or profession."NO - that's not it either.
Maybe we have to invent a new word to describe what we do. Any ideas?