Table 5. Keyword Searches.

Category	Keyword Searches
E-cigarette Use*$	vape OR ecig OR ecigarette OR vaping OR ejuice OR vapers OR (drip AND tip) OR dripping OR (eliquid AND flavor) OR (e AND juice) OR (e AND liquid)
E-cigarette Use for Smoking Cessation*	(smoke AND free) OR (off AND cigarettes) OR (ex AND smoker) OR (no AND analogs) OR (I AND quit)

^*note that we do not consider phrases in these keyword searches. We assume that a bigram phrase is equivalently represented as a Boolean AND. This assumption seems reasonable considering how short tweets are.

^$the query (e AND juice) is the preprocessed version of the word token “e-juice” with punctuation removed.