Social capital is the strength of the connections between people in a group. As the connections become stronger, the group can become more coopertive.
It is strengthen by day to day exchange of benefits, according to the Tit for Tat theory and by elevating the emotional emotional "chemistry". Because of the the problem of coordination, there is a limit to the number of connections each individual can hold. As the number of connected friends is growing, the time for social interaction is diminished for each member is reduced. Usualy people how are experts in social exchange, and invest a lot in social interaction, with care to as many members as they can, will gain more social capital, then people who do not engage in social interactions.
Going beyond the coordination paradox limits, can occur, when a person is becoming Socially recognized, and people are propagating a stories about him that he is a "socially good" person, so people will lend him help more easily. As he become leader, more will follow him, even if they do not know him personally.
As the networks of social objects (SON) is getting coherent, the work done by the group can be more coordinated.