"Is it worth my time?" Given that the compensation from an advisory board is equity in a private company with no actual market for it's securities, this is really the most important question. The likelihood that advisory board compensation will result in real financial compensation is very low, and yet the demands on your time are very real and can be significant. Is your time better spent in other areas?
"Is this company the most deserving of my generosity?" Because I enter into advisory relationships understanding that the likelihood of real compensation is so low, I evaluate whether to have such a role more from a perspective of how much I like the founder(s) and how much I want their product in my own life. If I don't really enjoy spending time with the founder(s), it's really not worth my time and energy. If I don't want the product in my own life, why would I spend time thinking about it and the business behind it?
To get clarity on those two main questions, I don't enter into advisory agreements immediately. I only do so after I have spent some time with the founder(s) on more than one occasion. And what I'm particularly observing is the founders' willingness and ability to receive feedback. Ideally, the founder updates you specifically on the actions taken and not-taken from the last time you were with them. We all observe differently, but I think it's paramount that you trust the advisor actually can implement your advice and counsel.
Is the Company "hoarding" advisors? More than 3 advisors to a Company is generally indicative that the founder is more interested in building social proof than getting advice and counsel. That can sometimes be acceptable in industries where proven expertise is really helpful and almost required in the early days of the business.
"Are expectations aligned?" Has the company articulated clearly the expectations of your time and involvement in a way you feel comfortable with being able to deliver upon?
Happy to speak to you in a quick call to answer any further questions on the topic.