In September of 2006 the subscriber list for ECOLOG-L reached 6,000. This week it went over 7,000. As you can perhaps imagine, this generates a lot of traffic for the University of Maryland's listserv server; only two other lists are larger, and they only have messages once a week or once a day. Thus I have to be careful not to send out more than a few messages per hour so as not to monopolize the server.
The membership growth of the Ecological Society of America has also increased steadily over the past few years, reaching 10,000 at the annual meeting last summer, and now is over 10,200. David Inouye, list owner and moderator, and Secretary of the ESA Board of Governors