Push poll
A push poll is a campaign technique where a poll is designed not to gather information but rather to alter the views of a voter. Rather than a poll it is disguised telemarketing. They are generally viewed as form of negative campaigning.
The mildest form of push poll are designed to remind voters of an issue. For instance a poll asking respondents to rank candidates based on their support of abortion will help to get voters thinking about that issue.
More negative are attacks on another candidate by using polls. These attacks often contain information that has no connection to reality.
Push poll questions are sometimes included in actual polls done by political parties. They are usually placed at the end of any such poll so as not to skew the results.
More often push polls are not included in another poll. These push polls tend to be very short with only a handful of questions so as to do as many calls as possible. The data obtained is discarded not analyzed. Any poll that does not ask demographic information such as age, income, or race is generally not a true poll but some form of advertising.
Perhaps the most famous alleged use of push polls is in the 2000 United States Republican Party primaries where it was alleged that George W. Bush's campaign used push polls to torpedo the campaign of Senator John McCain. Voters in South Carolina report being asked "Would you be more likely or less likely to vote for John McCain for president if you knew he had fathered an illegitimate black child?" an allegation that had no substance but planted the idea of undisclosed allegations in the minds of thousands of primary voters. In Michigan there were reports of polls portraying McCain as being anti-Catholic.
The main advantage of push polls is that they are an effective way of maligning an opponent while avoiding the appearance of negative campaigning that voters dislike. They are risky in that if it is ever proven that the polls were ordered by the campaign it would do serious damage to the candidate. Push polls are also expensive. It is of far higher cost per voter than radio or television commercials. They are thus most effective in smaller elections with only a few thousand voters such as party primaries.
These factors also make push polls not particularly attractive to private companies as a form of marketing.