Here are a few simple points of departure. But remember, this is a web. Connection through shared purpose or values Communities of purpose and practice present engaging opportunities for online communication. Reciprocity is critical helping people take the time to engage and participate in an exchange. Also, the ease of entry into a group where there is something in common can facilitate the process.
Many people tend to gravitate to the familiar.
Where there is shared purpose, there is an explicit link of commonality from which to build. Relationships have the opportunity for stability and people often hold each other accountable for showing up. When there is a connection, people come back and connect some more, building relationships and exchanging information together. For those more concerned with how their words will be judged, it can be more difficult. The ease of exit is very high until the relationships take form.