Happening a lot to me as well, they use a computer dialling system that automatically dials out when an operator is free. once it rings the operator is connected albeit a bit slowly. Save the marketing company time for the oprator to look at the number and dial it out manually. Also allows the company to keep the operators on their toes and not having breaks too.
Someone asked me to set-up a PABX to do the same thing. I didn't want to do it. Wonders of running a business where I can be ethical