Where category lines are shelved

yhlee writes:

I have an unrelated question based on this comment of dark_geisha's on Harlequin. She said: 'With regards to the Bombshell line, the editor started a thread about marketing it. I'd brought up the point that if they want to attract a more mainstream audience, they needed to pull the books out of the category romance aisle in the bookstore …' and I asked, 'I'm under the impression that they could do several titles if not more a month -- couldn't they pull out one or two a month for a year or something and see what happens? Or does it not work like this?
( Speculations about romance category novels, etc. )