What is a Blog?

What is a blog?

To be very frank ,I do not know the exact meaning though I am penning down my thoughts.
I referred to my dictionary to find out the meaning of the word Blog.
But unfortunately there is not the word Blog in my dictionary.
The I searched the net.
Yes it is there ; a list of definitions.
The most suitable definition according to me is:

" A shared online journal where people can post diary entries about their personal experiences and hobbies."

That, blog is a personal diary; then why should one person read another person's diary.

The other day it so happened that I did read a big shot's blog.
In that he has written- He went there, met such and such person, stayed in that hotel,had a lunch with Mr X and so on and so forth.

But is it worthwhile to read such scribblings?

That means one should have followers to read. If no follower ,then what happens?

May be these are all part of this century? - internet,3G, blog,chat ...

Only time will tell.