Wow, such a small percentage of spammees feeds a gigantic number of spammers. I wonder how First Orion managed to compile the data, did they conduct the survey with a telephone call? "Hi, I'm with First Orion and I'm conducting a survey on scam telemarketers..." Click.
Good point. However, judging by the number of scam and harassing calls I receive at home, I don't doubt the numbers stated.
I look through my call log at the end of the day and many times I have 5 or 6 I don't know. My cell doesn't even light up for any call outside of my address book. Here is a surprise, those no name callers never leave a message (rarely anyway). So that means my one little phone gets 6 unwanted calls a day. Believe me my number is only circulated by merchants that betray my trust, which we all experience whether or not we know it.
I would switch to a Telco that blocked spam at the PBX. However, none of them are going to do that because the advertisers would sue them. Scam artists are a different matter - illegal and unethical - but Telcos don't block them at the PBX either. It is a wack-a-mole exercise that would incur significant costs that they can not pass onto the customer. Grin a bear.