When one thinks of telemarketing it may not conjure the best impression but the truth of the matter is that it can be a very effective marketing tool for a business if used correctly. One of the best definitions of telemarketing that identifies it’s purpose an perils is below and pulled from the wikipedia:

Telemarketing is a form of direct marketing where a salesperson uses the telephone to solicit prospective customers to sell products or services.

The term is also negatively associated with various scams or frauds like multilevel marketing, pyramid schemes or with fraudulently overpriced products or services.

The prospective customers are identified and qualified by various means, including past purchase histories, previous requests for information, credit limit, competition entry forms or application forms. Names may also be purchased from another company's customer database, or obtained from a telephone directory or some other public list or forum. The qualification process is intended to find those prospective customers most likely to purchase the product or service being sold or advertised. Charitable organizations, alumni associations and political parties often use telemarketing to solicit donations.

Market survey companies often use telemarketing techniques to survey prospective or past customers of a client business to assess market acceptance or satisfaction with a particular product, service, brand or company. Public opinion polls are conducted in a similar manner.

Telemarketing techniques can also be applied to other forms of electronic marketing using e-mail or fax messages. (See spamming.)

Telemarketing is often criticized as being an unethical business practice as many companies make unsolicited calls and often engaged in high-pressure sales techniques, even though someone might repeatedly tell the sales representative he/she is not interested in the product or service. Such practices may be subject to regulatory or legislative controls related to consumer privacy and protection. In particular, telemarking in the U.S. is restricted by the Telephone Consumer Protection Act of 1991. Many professional associations of telemarketers do have codes of ethics and standards that member businesses follow to win public confidence.

In addition to the high-pressure sales pitches and the fact that calls are unsolicited, many people are upset that the calls come at an inconvenient time, such as during the dinner hour or while someone is watching television (more often than not, the call coming at a critical point in the show). Telemarketers often call during these times because they believe it is the best time to try to reach prospective customers. Sometimes, another telemarketer representing the same company – often, more experienced than the previous sales representative – might call a prospective customer (who had earlier rejected the offer) back shortly after the original call was terminated to try to win a sale, a further source of irritation and anger.

Some jurisdictions have implemented "Do Not Call" listings, either through industry organisations or legislation, in which consumers can indicate that they do not wish to be called by telemarketers. Legislative versions often provide for heavy penalties for companies calling individuals on these listings. The U.S. Federal Trade Commission has now implemented a National Do Not Call Registry in an attempt to reduce intrusive telemarketing on a national basis. Although challenged by telemarketing corporations and trade groups as a violation of commercial speech rights, the National Do Not Call Registry was upheld by the U.S. 10th Circuit Court of Appeals on February 17, 2004.

There are several methods that people use to avoid telemarketing calls. Using caller ID or a privacy manager can allow the targeted subscriber to identify the caller before the call is answered and make the decision not to answer. Answering machines and voicemail can also be used to screen calls, as telemarketers generally do not leave messages.

A few people have used foul language, even sadistic means (e.g., bringing the sales representative to an emotional breakdown) to berate telemarketers whom they believe should not have called in the first place and to discourage future calls.

The simplest solution is to ask to be added to the "Do Not Call" list and allow the representative to confirm the addition, before hanging up.