Advertising has always been a critical component of campaigning. But the practice of commercial marketing and the development of mass media have given new insight and discipline to political advertising. Advertising in politics, as in business, can be as simple as letting people know that a candidate or policy choice exists, just as soft drink commercials seek to develop "brand recognition" without making specific claims. Or political advertising can offer a more complex and detailed rationale for supporting a candidate or policy.
Simple name recognition is critical and may be decisive in local or "down-ballot" races. People are unlikely to vote for a candidate whose name they don't know. Candidates in local races and even in races for seats in the Texas Legislature usually do not receive the news coverage given gubernatorial and Congressional candidates. This problem also arises between elections, when coverage of statewide or national officials tends to crowd out coverage of state legislators, judges, and local officials. During campaigns, citizens usually follow only a few races at a time - the bother of following more than a few races increases quickly. Consequently, just getting people to recognize your name is the first and main challenge of many down-ballot candidates.
Advertising can involve both traditional and new media, including signs and billboards, print advertisements, direct mail, Web sites and e-mail, and radio and television spots. Usually, signs and billboards achieve only general name recognition, while other media theoretically allow presentation of a candidate's background or a policy's expected effects. Direct mail and candidate websites are particularly good for presenting more detailed information in a setting where the major constraint is how much time a citizen cares to spend reading.
Candidate Web sites have become standard features even of local races. Web sites often provide detailed policy positions, lists of endorsements, and candidate backgrounds - serving as clearinghouses of information about candidates. Web sites predominantly attract people who are already supporters, or at least leaning in the direction of the candidate whose Web site they are visiting.  Consequently, a candidate's site generally tries to reinforce the visitor's support, not to convert the already converted by disparaging the opposition. But in close races, negative campaigning is likely to reach Web sites, too.
The broadcast media are so expensive that candidates often attempt only simple positive name recognition (usually with a tag line like "Experience you can trust") or the most superficial treatment of their public policy positions. To win votes, many candidates are lured into negative advertising and even mudslinging. After all, it is much easier and quicker - and often more effective - to condemn your opponent as crooked, dishonest, or ineffectual than to offer detailed arguments about why you are the better candidate.
Campaign professionals usually produce different types of television "spots" to accomplish different purposes. Biography or "bio" ads introduce a candidate to voters, and are typically used early in a campaign. Contrast ads draw distinctions in policy or ideology by providing information about both candidates - with an eye, of course, to supporting the candidate producing the ad. Attack ads feature negative information about an opponent.
Candidates also pursue the same goals for which they advertise through non-media based events and activities like attending backyard barbecues, visiting citizens groups, and hosting community meetings. Any activities that give citizens a chance to see and relate to a candidate, and to understand something about that candidate, are critical to a campaign's advertising effort. There are tradeoffs, of course. A candidate can only attend so many barbecues, kiss so many babies, and meet so many people. Such "retail" campaigning must be combined with "wholesale" techniques like giving interviews with the news media and maintaining Web sites that can reach thousands, not mere tens or even hundreds, of voters.
3 See Don Lewicki and Tim Ziauckas, "The Digital Tea Leaves of Election 2000: The Internet and the Future of Presidential Politics" (First Monday, volume 5, number 12, December 2000; link: http://firstmonday.org/htbin/cgiwrap/bin/ojs/index.php/fm/article/view/818/727