PMIs claim that IQOS helps users switch from traditional cigarettes is unsupported by PMIs own research showing that very few users actually completely switched and significant dual use (using both cigarettes and IQOS) remained
Smoking Cessation: A Report of the Surgeon General [PDF - 9.8MB] Atlanta: U.S
Sekine K-T, Tomita R, Takeuchi S, Atsumi G, Saitoh H, Mizumoto H, Kiba A, Yamaoka N, Nishiguchi M, Hikichi Y, Kobayashi K (2012) Functional differentiation in the leucine-rich repeat domains of closely related plant virus-resistance proteins that recognize common Avr proteins
The three-day window is most commonly referenced in the context of transitioning from long-acting opioids such as methadone or fentanyl to buprenorphine treatment
The point is to use that information to help people quit smoking - something that's extremely beneficial but extremely difficult