paul said:
>   Could it be that a lot of PG's books are rarely read,
>   and the traffic seen for these books is due to people
>   downloading the whole collection simply to have it?

could be.

but i doubt there are many such people.

and is there any particular reason why you'd want to
doubt that there is actually an audience for a book?

if the only people who download unpopular books
are the ones who are downloading all books, then
you should have a number of unpopular books that
have the exact same download-count all the time...
so if you need to test your hypothesis, that's a way.

p.g. books are different from google books, in that
someone has spent a good deal of time on each one,
meaning that there has to be some intrinsic interest.

-bowerbird