1. Research shows that almost half of all political ads are completely ignored and those that are watched do not change opinions.

People have not only become jaded about ads generally, they are increasingly able to avoid seeing them at all thanks to the proliferation of television channels, digital video recorders and web ad blocking technologies.

According to research done at the University of California–Los Angeles and Stanford University, television viewers tune out almost half, 42 percent, of all campaign commercials—they never even bother to watch them at all.

A survey commissioned for the Republican-allied Crossroads Generation group focusing on younger voters found that only about 25 percent of respondents said they used TV ads as a source of political news. This was lower than the number of young people who said they got their news from comedy programs like The Daily Show in a separate survey commissioned by the College Republican National Committee.

According to the CRNC report, 40 percent of respondents said they used some form of digital video recorder like TiVo to watch television. A 2013 study by DVR manufacturer Motorola found that 74 percent of American DVR users say they purchased their devices in order to fast-forward commercials. Needless to say, people who want to pay money for the ability to skip commercials are not interested in watching them.

But even under ideal conditions outside of the political world, television advertising has been found to have very limited positive effects. The perfect illustration of this is the Super Bowl television spots that have become famous in their own right.