A typical Zogby presidential poll has a percentage error of +/- 5 percentage points. Zogby telephone polls are comparable in success to Gallup or Harris polls and correctly predicted the 2008 and 2012 general presidential elections, but the company's Internet polls are historically poor at predicting U.S. Electoral College results. Internet polling companies such as YouGov and Knowledge Networks had far more success predicting individual state results in the 2008 and 2012 presidential elections.
John Zogby has published a presidential tracking poll every election cycle since 1992 with two different companies, Zogby International and JZ Analytics. He became well-known for correctly predicting how close the 2000 election between Al Gore and George W. Bush would be. Other polling companies, including Harris International, predicted that Bush would win comfortably.
Before Zogby International was purchased by Brazilian market research conglomerate IBOPE Inteligencia in 2010, the company conducted both traditional telephone polls and Internet-based polls. Its Internet-based polls have been widely criticized and many poll aggregators, such as Nate Silver's FiveThirtyEight blog from ESPN, do not include Zogby polls in their analyses because Zogby companies encourage voters to volunteer to participate rather than scientifically polling voters at random, which violates the random sample theory of polling.
After Zogby International was purchased by IBOPE Inteligência in 2010, John Zogby left the company and formed JZ Analytics with several senior executives from Zogby International. JZ Analytics provides customers with telephone and Internet-based polling services, traditional and online focus group organization, intercept site-specific interview services, channel-checking third party analysis and rapid response SMS polling ability.