use graphics of a paperback book to sell their product?

It don't seem right to have a picture of one thing and
and sell something else.

Every time I see this it reminds me of a billboard that
was up in my hometown. It was a billboard that a new
car dealership put up.

They had a picture of their most expensive car as an
attention-getter. Below the picture they had the price
of their least expensive car. This was the car they were
going to sell you. It was their cheapest model.

To make a long story short! A customer took them to court
and he was awarded the high price car at the low price.

My question is way don't people that
sell e-books use a flat cover?

Regards,
Chugmug