Have you ever been to Penn. Station in New York City? The place is teeming with people, jostling around, jockeying for a position, waiting for their trains or their train doors to open so that they can rush in and get a good seat. Hundreds of thousands of people pass by and yet, there is very little interaction between them.  New Yorkers pride themselves on being people watchers.  They watch the actions of other ventolin where to buy ventolin in singapore inhaler no prescription asda people, their expressions, their style, their  conversations.  Voyeurs for pleasure,entertainment  or knowledge.  No interaction. Twitter can be the same way.  Recently I noticed that there were 20 people posting on a page. A comment was made to one person.   The other 19 people were   the equivalent of standing up on a soap box and giving a shout or all talking at once.   Just like Penn. Station.