First, I think we need to look at the value that the individual setting up a personal advisory board gets.
What I've found to be the most powerful force in the personal advisory board structure is accountability. It's an interesting phenomenon, that the individual who creates a personal advisory board gains more from just having someone (or a team of people) to "report to" than from the advice they might receive. It's like that old adage about writing down your goals. If you don't write them down, you're less likely to achieve them. The same is true here.
By just having a "personal advisory board", you will achieve what you set out to accomplish more times than not.
That's because you will be more realistic about what you can achieve when you have to say it out loud to those that you respect. Additionally, you're more likely to succeed at your goals when you know that failure means having to justify to others why you failed. Self-justification is easy. Facing up to others is hard.
Image by lunaweb via Flickr
And so the "equity" for the adviser is really just the satisfaction of seeing a friend or a respected colleague succeed. It doesn't require a lot of time and resources to be a "personal (accountability) adviser"; you just have to "be there" for them - a listening ear. And to me this means that the kind of personal adviser that one should seek out should be someone they have a good relationship with - because these are the people that want to help. And they're the ones that gain value (aka equity appreciation) in helping others.
On a related note, I find that many of the "social tools" that we use online are an extension of this accountability factor. Your "social graph" is in many ways your personal advisory board.
Imagine how accountable you would feel if you tweeted your goals. That's the power of "social media". Give it a try. Tweet your #goals. Your advisory board is listening.