Popularity of communities and group on Internet

Communities (virtual) are popular because:
1. The communities and groups offer conversational style of learning, which is inherently a social and dialogical process (Duffy, 1996). We tend to learn better or naturally by seeking out opinions and ideas from others.
Examples - (a) I find travelling by train more comfortable (short distance of course) than by Air, because, Trains in India provide an opportunity to open up freely and interact rather than the Air. - people tend to enjoy social interaction (b) During my travel overseas a few years back, I landed at Bangkok airport in the midnight and I had to take a connecting flight to Manila. I had difficult time then at the airport, since all information was available on the screen boards rather than people-to-people interaction we have in India. I realize we enjoy the dialogical process. Hence the communities will flourish.
2. Communities are also form of Informal learning and the learning results are from the activities related to work or leisure. It is unstructured most of the time and hence appeals to majority of the members.
The communities thus offer informal learning through dialogical process. I guess!!