We're probably going to need to look back a bit further than Cybererotica et al.
Of course we have to distinguish between internet porn and a porn web site -
the internet is decades older than the web. The first graphical web browsers
became available in late 1993 (
http://www.w3.org/People/Berners-Lee/WorldWideWeb.html ).
That same year, Tim O'Reilly launched the first commercial site (mainstream).
By the following year, the first goverment officials were busted downloading
porn on government computers.
By 1997, when I started in the business, we estimated that there were about
100,000 non-free sites, 30% of those under AdultCheck. By this point in 1997
80% of the traffic and 90% of the revenue on the web was adult related.
The age of Cybererotica, X-Pays, etc. followed soon after. Though
cybererotica.com was registered in February of 1996, this was just three weeks
before adultcheck.com was registered for the first major AVS system and porn
was already well established on the web.
AdultCheck, registered in March of 1996, was a major turning point for the
industry because it meant you could get paid for your adult site memberships
without having to get a merchant account - meaning any smuck could launch
an adult site from their living room over the weekend. The first porn site,
with images, would have been at least two years earlier, in 1994. Which site
it was would depend on the exact definition of "porn site", as browsers were
able to download images for display in a seperate window starting with the
first web browser in 1991. (Finished Christmas 1990, it wasn't released until March 1991).
Playboy scans in GIF format were available on Compuserve by then, so it's
reasonable to assume that in wouldn't have taken long for Berners-Lee or one
of those first web pioneers to jokingly put a nude image on their site for one
of their friends to see. So the first porn accessible via a web browser was probably someone messing around in 1991 and if so they'll probably never
admit to it. The first COMMERCIAL porn site would probably have appeared in
late 1994 or early 1995, a year and a half before cybererotica. This would
coincide with the release of Netscape, then called Mozilla. The first site
DEVOTED to porn was probably also late 1994, when new Netscape users
coming from the porn filled environs of Compuserve and Prodigy came to the
web.
A whois on sizzle.com appears to give a bogus registration date of Wed Apr 26
00:00:00 1995, as indicated not just by the bogus 00:00:00, but by sizzle.com's
own claim on their web site which says they launched in 1996 along with
Cybererotica and AdultCheck. I'm curious about this, so I sent an email to
the owners of sizzle.com, whose umbrella brand is sexinc.com.