In consideration of our entire customer base, we exclude "adult" material from appearing in some searches and best seller lists. Since these lists are generated using sales ranks, adult materials must also be excluded from that feature.
Hence, if you have further questions, kindly write back to us.
My main quibble with Probst is that with a Barnes & Noble sales ranking of lower than 300,000 his book would not be found by anyone searching for a popular book, and all we're talking about is bragging rights, not anything which would truly affect sales of his book. A minor quibble is I don't see how romance novels of any description are not Adult content. Amazon has been keeping adult fiction off general searches for a long time, adding non-traditional gender fiction to that ban seems to me like Amazon's way of accepting those novels into the mainstream of the romance genre, something to be welcomed.
On those rare occasions when I search for a novel by popularity, I usually stick with sales rankings 100 and better. Most lists aren't even that generous. Mostly I search by author or title or genre, and don't pay any attention to rankings.
I had no problem finding The Filly on amazon.com with a simple title search. Amazon's auto-completion kicked in to help me. Ditto with an author search. See it for yourself here. Only three copies in stock as of this writing, though.
I understand those folks who think Amazon belongs in hell and boycotted and picketed and banned for singling out non-traditional gender works. There are plenty of other sources for books, knock yourself out. Frankly, IMHO your best protest is to buy every copy of the victim books from Amazon, show that the lack of a sales ranking doesn't mean squat to an intelligent reader.