Only 57 percent of respondents nationwide said that live television was their primary method of watching video content, compared with 17 percent who said they mostly watched content recorded from Tivo or DVR and 9 percent who said they relied on DVDs.

Among voters who watch television through DVR, Tivo or other time-shifting methods, 88 percent say they skip over commercials three-quarters of the time or more. Fifty-nine percent say they skip ads all the time.

That suggests tried-and-true advertising tactics – such as a high-dollar TV blitz in the final weeks of a campaign – may be less effective for candidates in 2012, as voters are increasingly able to customize when and where they consume media.