i'd be lying if i said i never checked out these sites.
however as a result of my curiosity i've been exposed to both authors and entire genres that i never knew existed. i now have a full amazon wishlist and will be heading to a convention next month where i'll be buying copies of some of the books directly from the authors. stuff that i never would have bought otherwise due to either price or available samples not giving me a good feel for the book.
i am now directly involved in helping the aforementioned publisher market their books in an official,albeit underground capacity due to their "pirate" program. the bizarro genre is one i never would have given the time of day to before.
i wish more pubs would think outside the box with marketing or set up "ebook club" subscriptions and the like. if i could give a pub say $20 a month and receive all their books for that month or something i'd do it in a heartbeat. the traditional ways aren't working anymore. unless you're stephen king, good luck getting your book noticed. if authors are resorting to unorthodox marketing and seeing success from it, more power to them.
and just for the record, 99.98% of my ebooks are legitimately aquired but if someone could point me to legitimate sources for something like Pohl's HeeChee saga I'm all ears...