ÒIt costs Eight times as much to get a customer as it does to keep oneÉÓ
Where the word Eight appears, you can insert Ten, Twenty, Thirty Six or whichever you feel is appropriate.
As with so many ÒfactsÓ and statistics they are largely based on best guesses or Chinese whispers, what is certain however, is that it is cheaper to keep existing customers happy than it is to go and find new one.