Yes. Playboy made an announcement saying that they were shifting out of porn and into other things as a way to stay afloat, because of their recent loss of sales.
I write porn & erotica and sell them on Amazon. I'm friends with about 30 other authors of it, and know via social media about 3,000 other authors of it. Here's what I've personally seen:
After June 015:
Why the change?
In the case of Amazon, in 2010 Amazon had a 18+ Adult Only section.
In 2012 Amazon added Google Adds to their site and was immediately blacklisted by Google's Panda.
To get the Amazon website re-indexed on Google, Google DEMANDED Amazon remove the adult section, so Amazon deleted the entire section, books and all. Thousands of Por authors had their accounts banned from Amazon in the process.
In October 2013, Google decided it did not like Monster Porn and un indexed every site on the net offering it for sale - including Amazon once again. Amazon responded by deleting all Monster Porn off it's site and banning author accounts.
In February 2014, Google decided it didn't like BDSM and un indexed every site on the net offering it for sale - including Amazon, yet again. Amazon responded by deleting all Hard Core BDSM off it's site (allowing Vanilla BDSM look-alikes like 50 Shades) and banning author accounts.
In June 2014 Amazon rolled out Kindle Unlimited, a program that paid authors a huge royalty every time someone read 10% of their book, and authors gamed the system by flooding Amazon with 10 page porn - every time some one looked at the front cover, without even opening the book, it counts as 10% read in a 10 page book.
In March 2015 - Amazon sent an email out to authors requesting them to please remove all books under 5,000 words long ( Amazon counts 311 words per page so a 10 page book is only 3,110 words long) and stating that Amazon would begin reviewing all books under 50 pages before allowing publication. Ending to say that if authors did not stop publishing "Scamlettes" (Amazon's term) that they would be forced to change the KU payout system
In June 2015 Amazon did as they threatened and changed the payout system (which now pays .0003c per page read and authors require readers to READ a whopping 500+ pages in order to earn $1 now.
So, I can't speak for other areas of the adult industry and why sales are down, but I know why sales are down on the segment of the industry I' working in.