Great TED talk about how social networks affect our lives and what we can do to take advantage of this fact. Nicholas Christakis argues that many traits can easily spread from person to person and that your location within a network might impact your life in a way you would never think of.
If you don’t have 18 minutes to watch this video, I recommend you start watching from the 13th minute. The conclusion is most important and it comes around the 17th minute:
I think we form social networks because the benefits of a connected life outweigh the costs. [...] The spread of good and valuable things is required to sustain the nourish of a social network. Similarly, social networks are required for the spread of good and valuable things like love, and kindness, and happiness, and altruism, and ideas. [...] Social networks are fundamentally related to goodness [...] and what the world needs now is more connections.
