[manephelien]

I haven't seen a wider leading, but I have seen bigger fonts. Some books are as big as 18pt, when a standard paperback is between 8 and 12 pt. Very good for people whose vision is deteriorating. My mother who's in her sixties used to prefer paperbacks, but because her vision isn't as good as it was, she finds hardbacks more enjoyable to read these days.

A hardback often costs at least twice as much as a paperback, so the difference in materials is covered. It's also harder to get shelf space for a hardback once the paperback has come out, since hardbacks take more space.