I think the computer runs through a series of numbers for a given area code and exchange one at a time until it gets a ringtone and then the message kicks on automatically with the answer. Most never leave a voice message and when they do, it's animated just like when you pick up. The one I get most frequently goes, "This is an important call for so-and-so such-and-such. If you are not this person, you can ignore this call. If you are this person, please stay on the line for this important message from whatever-the-sales-pitch-is." For listed land-lines, they've got your name already. For unlisted ones, it's just a matter of having the database that reveals the person's name. If they get you to pick up, and you stay on the line long enough, a human comes on, but I've never let it get that far.
There is a company that recently moved into some local offices and all they are is a boiler room full of phone lines. They somehow access new car sales databases and when an owner's warranty is about to expire, they call and attempt to sell you an extended warranty. The BBB has given them an "F" rating, so they move around from state-to-state to keep from getting shut down. With all the empty retail and office space, landlords and communities welcome them, but they are more or less a giant scam perpetrated on an unsuspecting public. Their warranties are crap and the complaints go mostly unresolved. This is only one of many types of telemarketing scam.
'07 CPB Blue; ZGST windscreen with MRA X-screen adjustable spoiler, tube bar adaptor, PC III, ATRE,BMC air filter, modified stock seat with 2nd Look cover,Scorpion Flame Ti slip-ons, Galfer rotors front and rear, braided-stainless lines, C-F 10R front fender, C-F hugger, C-F inner fairing panels, painted foreman's fins with faux C-F inlay, polished rim lips wired for heated gear and accessories, Givi V35 side bags and E41 topcase with SW-Motech qd mounts