and that seems to help a lot... what I find interesting is that he is charming the audience in the 70s style, when singers where all but directly flirting with the audience...
at least for popular musicians in Europe that was pretty much the norm (e.g. Smokie, Suzi Quatro,Suzi Quatro and Chris Norman)
some of them became "victims" (they were doing it so heavy handedly that it became ridiculous...) e.g. Modern Talking's Dieter Bohlen -- blond guy (I mean... those glimpses are embarrassing...)
there is an art to doing it right, and I think Justin Bieber is very talented in this regard (maybe more so than as a vocalist -- his voice does appear in-changing so this may not be the best time to judge but... it does not strike me as... earth-shattering)