I don't know what decision-making process is used so i have no doubt that a forum admin or staff or founder will provide to you a more accurate answer, so the answer below is just what i suppose:
Someone become forum advisor or forum staff or admin if the founders of this site decides so ( i guess)
I suppose :
Forum advisor are promoted by the forum staff and admin
Forum admin and/or forum staff are only promoted by the founders (i suppose)
I think there is no "carreer plan" here
My advices :
- Follow the forum rules
- Behave fairly and nicely
- Be active in forum life
- Provide quality answers
- Don't ask promotions
Maybe one day, the staff will decide - or not - to promote you.
Helping people should be a matter of convictions, not a roundabout way to satify a need for power ( we are not politicians
)