A controversial statement...
Often we hear of a job given through 'knowing' the right person. Or information shared. Or an invitation to an event filled with power brokers. It's true - most of us would rather work with and share good fortune with folks we know and like. It's not chance that has affords us these opportunities; most of the time, it's steady networking effort and good relationship skills.
But does that mean you should only look 'upward' at those who are already powerful/influential when building your network?
First - most folks grow into their influence and position. Those who were part of their communities along the way are more trusted than those who came along with the success. Your inner circles and friendships are not a result of success - success is a result of your circles and friendships. I'd rather talk with someone who has believed in me all along than someone who is hoping to get close and pump me for the secret of my success.
Secondly - everyone you meet has the potential to add value/information/other people to your community as you do for theirs. I'm not saying befriend everyone. I am counselling that you don't eliminate folks for potential inclusion in your community based on their current level of success (however you define it). That would be like me eliminating each guy I meet as 'unmarriagable'... which doesn't leave me with any males to have as a friend, colleague or even repairman!
Besides, you meet folks at a point in time for them and for you. As your goals/needs change, so do theirs. As your success or explorations move on, so do theirs.
It's who you know... because there are so many definitions of 'who' you'll need along the journey.