According to stats from a Folio's 2009 e-Media Survey, paid content is the 4th largest electronic media revenue stream for magazines which is not impressive, but the profit margins are. Turns out 50% of respondents said paid content had profit margins of more than 30%. So, it's worth their while pushing the paid content envelope a bit further, wouldn't you say?The only other online revenue source that scored even higher, was blog sponsorships, with 56% of magazine execs saying these had profit m...