It doesn't communicate growth -- there is nothing to compare against. If you were going to do that, you'd simply provide a something like YOY% change in revenue.

A run rate is just inflating/fabricating PAST revenue by speculating on the FUTURE. Refer to my helpful chart:

  |  / <- SHOW THIS NUMBER TO INVESTORS, PRETEND IT WILL GO ON FOREVER
  | /
  |/   <- HIDE THIS NUMBER, TOO LOW
  +---