Smokers provide three weeks (1 week pre-quit, 2 weeks post-quit) of brief 4x daily, real-time web-survey reports of recent cigarette use, NRT use, and other measures not relevant to this study's purpose on the participants' smartphones. At two weeks post-quit, smokers are scheduled for a laboratory visit where participants provide an additional report via staff interview of any smoking during the two-week smoking cessation period.