The bottom line? According to multiple, peer-reviewed studies, simply being in an open network instead of a closed one is the best predictor of career success.
In the chart, the further to the right you go toward a closed network, the more you repeatedly hear the same ideas, which reaffirm what you already believe. The further left you go toward an open network, the more you’re exposed to new ideas. People to the left are significantly more successful than those to the right.
In fact, the study shows that half of the predicted difference in career success (i.e., promotion, compensation, industry recognition) is due to this one variable. (Source)
Open Networks promote Serendipitous Exchange