The most common obstacle to completing the voter registration process, cited by 30 percent of respondents, was missing the registration deadline. The number of voters who received their ballot electronically increased significantly: 52 percent of respondents in 2012 compared with 22 percent in 2010. By October 15, slightly more than 40 percent of respondents had returned their ballots. Fifteen percent of respondents returned ballots electronically—either by fax, email, or uploading their ballot onto their state’s official election website.
via pewstates.org