Telegram is a measure of Sucess for icos cause icos need a community and most team developers build their community on telegram, from telegram you can tell if the admins of a project are serious or not, it is easier to communicate on telegram than this forum,  you get many active supporters of your projects on telegram. Also many icos run airdrops in telegram so they get lots of new users coming for the airdrops, but  if they like the projects they invest in them as well, and also telegram build trust among investors cause when you see an active telegram group with much people ,you can HV trust in that project and also invest in it