The telemarketing industry is geared towards residential:
mortgage refi's
credit card offer
phone companies
consumer survery
charities
Not much is geared towards businesses since marketers have to get past gatekeepers.
Hmm, you should answer my phone someday.... marketers a few times a day. That said, I survive it, doesn't bother me much, I usually tell them that 'oh, Mr Quigley handles that, and unfortunately, he's not in'. Next time they call, and ask for Mr Quigley, I know it's a marketeer, no big deal.
The company next to me actually has a voicemail box setup for Mr. Quigley.
Dan