There's nothing wrong with long copy + other persuasive techniques (imo any way) -- the danger comes when those techniques are used to peddle SNAKE OIL.

The danger (+ temptation) comes when the marketer gets the 'brilliant' idea (?) that persuasive techniques WORK, whether the product/service being pushed is valuable, OR NOT!

Also, some of the more 'clever' (read: manipulative) persuasive techniques are GLORIFIED by the marketers -- with the sense that they allow the marketer to 'get one over on' the audience. With a 'hehe' gloating attitude about the 'unfair' sneakiness of it all.

The mindset being, if it doesn't work sufficiently using the legitimate route, then just switch over to the sneaky route -- and join the huckster crowd... morals b'damned.

My 2nd point being, th world may be thinking that about you (already), even if you're still on the legitimate side.

-- TW