Impact of E-cigarette Characteristics on Reinforcement and Tobacco Use Patterns

Inclusion criteria include * adults who have been smoking daily * interested in using e-cigarettes * who have a smartphone that can receive text messages and access to the internet or has an e-mail account that they check daily Exclusion criteria include * minimal prior e-cigarette use * use of tobacco products other than cigarettes * current use of cessation medications * pregnant, trying to become pregnant, or breastfeeding, * recent history of cardiovascular distress in the last three months (e.g., arrhythmia, heart attack, stroke, uncontrolled hypertension), * household member currently enrolled in the study.