This whole Telemarketing thing strikes a nerve with me since I work in a
similar industry.

I work for a marketing research firm. We conduct opinion polls and recruit
consumers to participate in taste tests, focus groups, etc. We never, ever,
try to sell anything and we train our interviewers to be respectful and
considerate.

But, as you can imagine, laws like the ones many of the people in this forum
are clamoring for would kill our industry, undercutting the primary avenue
the consumer can use to share his/her opinions with the manufacturers and
providers of the products and services (s)he consumes.

It's a quandry.

I also dislike having my dinner interrupted by an unsolicited phone-spam. Of
course, I often just let the machine answer it. :shrug: What's the point of
having a phone if you don't want people to call you? Maybe they're selling
something you want.

Anyway - sorry about the rant - I can answer the original question. When a
telemarketing firm calls you during the day and hangs up when you answer,
it's because they don't want to talk to you. They're conducting a Message
Campaign, in which all they try to do is leave messages on people's
answering machines. There is no large phone center with hundreds of agents;
there is just a PC, connected via a phone switch to a telephone system. It
calls answering machines and leaves messages.

This technique is often used by the time-share resort industry. The message
usually says something like, "Sorry I missed you. Please call me back so I
can tell you about the vacation you've won." Then, when you call back,
you're invited to the 90-minute sales presentation in Nowhere, MO, three
hours from your house.

They figure that this is cheaper than paying people to call you... This way
the live operator only talks to live prospects.