Table 1.

Definitions for each theme and example paraphrased posts.

Theme	Definition	Paraphrased post
Device features	Mentions of hardware (eg, disposable or reusable battery), product features (eg, color of the device), specifications, and quality of the product.	Puff Bar is a disposable, prefilled, and precharged vape, but JUUL has disposable pods and a reusable battery.
Flavors	Mentions of flavors (eg, specific fruit, sweet, savory, candy, alcohol, coffee, tobacco, menthol, or mint) offered by each brand or enjoyed by the consumer.	This banana-flavored Puff Bar e-cigarette tastes amazing compared to a tobacco-flavored JUUL e-cigarette.
Longevity	Mentions of how long a Puff Bar or JUUL product lasts, including the duration and number of puffs.	This Puff Bar only lasts 1 day, but I cannot afford a pack of JUUL pods that last 2 weeks.
Price	Mentions of monetary amounts or affordability of JUUL and Puff Bar products.	Puff Bar [products] cost only US $8 and are cheaper than JUUL [products].
Youth use	Mentions of youth (aged under 21 years) and mentions of children, youth, or teenagers using a Puff Bar or JUUL product or other e-cigarette products during school time or in school premises. Posts may also raise concerns over youth use of vaping products in general.	[I] found a JUUL [e-cigarette] in the high school bathroom in the morning and a Puff Bar [e-cigarette] again later.
Switching	Mentions of quitting 1 product for the other.	I quit [using] JUUL [e-cigarettes], but now I just use Puff Bar [e-cigarettes] every day.
Dual use	Mentions of using both Puff Bar and JUUL products.	[I am] hitting my JUUL [e-cigarette] for breakfast and my pink lemonade Puff Bar [e-cigarette] for dinner.
Nicotine concentration	Mentions of nicotine concentration or nicotine salt levels.	I can get just as much nicotine from Puff Bar [e-cigarettes] as my JUUL [e-cigarette] with even higher nicotine delivery.
Health risks	Mentions of Puff Bar being more harmful than other e-cigarettes (eg, JUUL) or vice versa, and of negative health consequences of Puff Bar products. This may include mentions of people harming themselves by using JUUL or Puff Bar products.	Puff Bar and JUUL [e-cigarettes] made my chest hurt so bad, but I still use my vape.
Confusion	Mentions of confusion over the differences between Puff Bar products and other e-cigarettes (eg, JUUL).	She was holding a Puff Bar or maybe it was a disposable JUUL [e-cigarette]?