Dunbar’s Law says a group or tribe can manage no more than 150 relationships before it needs to split into two or more groups.  Seth Godin’s blog post places the theory in context.  If we can only maintain 150 relations (maximum) then who is in the tribe (no Facebook and Twitter do not equate to a bonus).  Be purposeful when building the tribe, no room for those who do not bring something remarkable.  Start by asking who inspires and who impresses.  Those who inspire are doing something for the greater good that impacts others, the impressers might have great stories but do they add value to the circle?  We do not need everyone and cannot maintain a relationship with them anyway so select wisely.