Here's an interesting fact:

"In 2006, $4.1 billion was spent on telemarketing in Canada, generating $26.1 billion in sales and creating 155,000 jobs."

There's your answer about why you still get annoyed with Telemarketing calls constantly even though you have never bought anything over the phone.

The CRTC (Canadian Radio-television and Telecommunications Commission) is actually enforcing this new "do-not-call list" starting this fall. I doubt it is going to change anything but we'll see.

More on it here, on CBC.ca