This Modern World (apologies to 
Tom Tomorrow)
Via 
Alternet we learn:
Call Waiting and Call Forwarding cost less then $.01 cent to offer yet the company charges $4-$7 for such features. 
I've got another.  They charge one dollar per month to not make your number public.  That is, a human being when setting up your account clicks on a choice of "no" for publication, then you are charged a dollar a month FOREVER for them not to go in and click it again.
That's not a "service."  That's extortion, pure and simple.  And they get tens of millions (at least) EVERY MONTH from this scam.