Smoking Cessation Self-Help for Dual Users of Tobacco Cigarettes and E-Cigarettes

Inclusion Criteria: * Study I - First Phase - No Longer Recruiting * Greater than 1 year history of daily smoking * 1 month or more of e-cigarette use * Able to speak and read English * (1) current dual users (of tobacco cigarettes and e-cigarettes) without interest in quitting smoking; (2) current dual users who have attempted, but not quit smoking; (3) current e-cigarette users who have successfully quit smoking; and (4) former dual users who have quit both products. * Study I - Second Phase - No Longer Recruiting * Current dual users (of tobacco cigarettes and e-cigarettes) * Smoking at least one cigarette per day over the past year * Using e-cigarettes at least once per week over the past month * Not currently enrolled in a face-to-face smoking cessation program * Able to speak and read English * Study II - No Longer Recruiting * Current dual users (of tobacco cigarettes and e-cigarettes) * Smoking at least one cigarette per week over the past year * Using e-cigarettes at least once per week over the past month * Not currently enrolled in a face-to-face smoking cessation program * Able to speak and read English