I am a telemarketer. "Why?" you ask. The reasons are several. Firstly, I am in dire need of money. Secondly, of the 120 resumes I dropped off, only telemarketing places called me back. It's not that I have no experience of that I am a dunce, I have yet to even get a B at university, but resumes dropped off at stores is a very poor way of getting a job. I am leaving town in about a week, so there is no point in investing lots of effort in finding a decent job. Especially since any decent employer doesn't deserve to have their new employee quit after a week on the job.
Now, working for a few days as a telemarketer, I have learned a few things that all the telemarketing haters ought to know. As has been rightly pointed out previously, it is an awful job - the very lowest legitimate profession. Chances are, the callers don't even make minimum wage unless they sell a certain amount. For instance, there will be 'cause' for me to be fired if, in any hour after my eighth day, I earn less than $40 in each hour. That means they can toss me out the door for one unlucky hour. I get no job benefits and no job security. I suffer abuse from people who I call and from supervisors who expect me to lie like my coworkers do. They do this in order to keep the jobs that they need. I have the benefit of not needing money badly enough to be worried about keeping this job. If that were not the case, I would have to pull out all the stops to sell as much of whatever we happen to be selling on a particular day as possible.
There's a real conundrum involved with telemarketing. Most of what I 'sell' are donations to charities. It is an entirely legitimate thing, I've checked it out, but the sad fact remains that the charity only ends up getting about 35% of the donation once a 10% fee is subtracted by the telemarketing firm, in addition to administrative charges: my measly salary included. The rate of staff turnover is incredibly high, since the job security is nil and almost any other job is better, so even the good callers are constantly dragged down by those who, like me, have only a few days experience. Puny bonuses await those who really excel at the art of telemarketing. The conundrum, of course, is whether you should abuse telemarketers or not. Malice directed at the actual person calling is probably misplaced. Relatively few employed people are in a worse position than your average telemarketer. Imagine if your boss could fire you if you messed up in the next hour.
I'd advise you to be nice to telemarketers, or as nice as you can muster. Don't actually give to charities over the phone, though, as they get only a tiny fraction of what you donate. I suppose it's better than not donating at all, and direct marketers do make it easy to donate, but actually giving your money or, even better, your time and ability to a charitable organization. The real question is whether you want to help out the poor sap who is sitting in their cubicle.
The workday of a telemarketer is something like this: your dumb terminal connects to the huge, evil dialing computer that tries to weed out answering machines and busy signals so that most of the things you say "Hello" to are people. Then, you either read some pre-written pitch or wing it, depending on your skill, mood, and level of frustration. All day, you do the same thing over and over but, if you want to keep your job, you need to make it sound like it is still interesting to you on call number 500. It helps to be telemarketing for charity. People are much less abusive to you and you can feel as if you are making a contribution that is at least partly positive. Telemarketers for profit must have it even worse.
In the end, I am deeply ambivalent about telemarketing. Hanging up on the callers and abusing them might cost someone who really needs the money their job. At the same time, there are plenty of scams and such to be wary of. Never give money over the phone. No legitimate telemarketing firm will require you to. Read up on the laws regarding telemarketing in your jurisdiction. Finally, remember that the person who has called you (or, rather, the person connected to the computer that has called you) is a human being who deserves a certain level of respect and courtesy. To treat them as such serves as a measure of your own empathy and moral worth.