If U2 were still putting out original B-sides on singles, I would be hunting for them, just for those tunes (the singles)... Kind of self defeating to want to be a pop act without singles with added value, or frequent update.
Pop acts issue singles almost consistently. There surely are statistics as to how this is done, dividing the year, but airplay and tv/internet presence is paramount, you can't be a mass-pushing pop act starting from scratch (with your target audience) every 4 or 5 years, that's illogical. :-/