Not in my experience, but I would imagine that is genre-specific. I don't sell anywhere near the amount of print books as I do e-books. In fact, Evernight doesn't send much to print at all because the sales don't make up for the costs. Almost all my Siren books went to print but I sold a fraction of those as compared to the e-book sales. I don't know about credibility. I write in a niche market that has always been an e-book market mostly, so I'm probably not the best person to answer that aspect of having a book in print.
I think the anonymity of the Kindle makes reading romance and more so erotica much more ubiquitously-available. I would much rather leave a Kindle sitting on my desk at work, than
Deflowering Joan.
Good book, incidentally.
Not actually a book. Can't lie. Nor can I Google it, at my desk at work, to confirm whether it is, in fact, a book or not. Anyone with more latitude wanting to expound on the subject, feel free.
I personally have interest
only in publishing hard-copy. I know e-books represent a massive portion of total book sales, but I could honestly take it or leave it — I will see my books on the shelves of bookstores, damn it.