It helps if you have your phone registered on the "Do not call" list. However this does not totally eliminate calls, just thins them out some. Lol!
The worst ones are the auto dialer ones that used to call us on all 4 lines where I used to work. And of course you have to answer a business phone. We learned eventually that many of them had a message at the end of the spiel that if you press 2 (or whatever) they would remove your # from their list.