They offer contact with colleagues interested in the same topic. Any Email sent to the list by participants is viewed by all current members. This allows for direct contact with colleagues by Email, and is a valuable source of such contacts. The quality of information varies from list to list, but also varies over time depending on who is contributing at the time. New members generally observe, for a while, and begin sending messages only when they have a feel for the character of the list.
Some lists deteriorate when too much traffic congests everyone's mailboxes.
When that happens, some members will often form a new list on a more specific topic. A good method of finding contact with colleagues is to fish around among listserves until you find one that suits your interest. Once you have joined an appropriate list, you can ask if anyone has information of the kind you are seeking. Instructions for joining a list may be found at some of the lists of lists, such as TileNet . None of the lists of lists below includes all of the listserves available, so it is wise to look through several of them.