While he may not be a "middle aged folkie's "cup of tea" , Bieber sold 15 million albums before his 18th birthday. On YouTube, his song "Baby ft. Ludacris has 805,804,019 hits", so someone is watching, globally (while it has 3,220,235 dislikes, IMO, a small # compared to the total number of views).

Canadian singer-song writer, Gordon Lightfoot sold 10 million records in his career since the 60's.

I am not saying Bieber is better than Lightfoot. But, the success for this young fellow is not too shabby.