3% in May and 22.92% in July) but only a small percentage of the therefore total view counts (2.63% in May and 2.67% in July). These primarily showed women smoking seductively; several directed viewers to other Web sites for more explicitly sexual content (Clip1493, 2009; Doofman45, 2009; IsabelleEvans398, 2009). Many videos portraying smoking positively also referenced a specific brand of cigarettes (Table 4). While no antismoking videos mentioned brands, 20 (41.6%) of the positive videos viewed in May and 25 (47.1%) in July mentioned a brand. The most popular brand mentioned was Marlboro, which was mentioned in about 50% of videos in this genre in both time periods. In May, vintage cigarette commercials accounted for 30% (6) of videos with brand references and 33.

7% (1,761,434) of the total number of views that contained a brand reference. In July, seven vintage cigarette commercials accounted for 28% of the brand references and 43% (2,258,296) of the total number of views containing a brand reference. No vintage cigarette commercials included a Surgeon General��s warning. Table 4. Brand references on YouTube May 2009 and July 2009 When examining brand references, ENDS (��e-cigarettes��) videos, while a very small percentage of the total overall videos, increased in relative popularity. In the May sample, there were two videos, out of a total of four in the genre, that promoted ENDS and also mentioned a brand, with a total view count of 93,592. By July, five out of five ENDS promotion videos mentioned a brand, with a total view count of 366,324, a nearly fourfold increase.

In these videos, ENDS were promoted as healthier alternatives to smoking tobacco. Limitations Our study has limitations. YouTube is always rapidly changing, and our sample captured only a portion of material available during two timeframes, albeit material most likely to be viewed first if our search terms were entered. There were approximately 315,500 total hits (probably many duplicative) from which samples were selected. The 160 videos we viewed may not represent the full range of negative and positive smoking videos on YouTube. In coding the videos, we coded vintage commercials as positive because they typically show smoking as fun, desirable, etc.; however, it is possible that some viewers watching these ads might interpret them differently. Other search terms might have retrieved a different set of videos.

In future studies, a wider variety of terms could be searched across more timepoints. Although we were able to retrieve the view counts Drug_discovery of each video in the sample, there is no way of knowing how many unique viewers this number represents. Conceivably, a few viewers watching video repeatedly could significantly increase view counts while not representing more viewers.