Has to be the content that they are writing and posting. I will follow them if i enjoyed it and would like to read more of their work.
Sometimes it could be someone following you and commenting and voting on you regularly. It is more out of good manners sometimes to show a thank you for their support. It all depends really and it is about engaging and getting on with everyone.
I have never chased a whale as I reckon you would be wasting your time but if they were a good entertaining writer then I would probably follow them. Account size should have nothing to do with it is what I am really trying to say.
Thanks for the honest answer! I appreciate it.