In political campaigns, an attack ad is an advertisement designed to wage a personal attack against an opposing candidate or political party in order to gain support for the attacking candidate and attract voters. Attack ads often form part of negative campaigning or smear campaigns, and in large or well-financed campaigns, may be disseminated via mass media. An attack ad will generally unfairly criticize an opponent's political platform, usually by pointing out its faults. Often the ad will simply make use of innuendo, based on opposition research.