Well few things that does motivates me to answer the questions in here
The type of question - It should be logical.
Have value and my answer will help that person who asks it.
How the user presents the questions that matters as well (is it serious question that has any kind of value or just ask a random question out of nowhere)
I answer most of those questions, that I have encountered in my life and will help the user learn something from it.
Steem related questions gets priority in my answering list as well.
Those Bonus UPVotes from Muisng does really work more too.
And overall the connection we do make with each other that is what matters.