• by elizabeth , Bill Tancer , October 2, 2008

In 2006, the federal government declared that the Internet was 99 percent porn-free, based on a study by Professor Philip Stark of University of California, Berkeley. Yet, other studies have put pornographic Web visits as high as 40 percent of all online activity.

One report estimated the sector at $97 billion a year. But accurate figures on revenue or usage are difficult to come by. The producers are known to overreport, and consumers - well, let's just say they're likely to underreport.

Since this data proved so elusive using traditional market research, I became fascinated with the topic.There are more than 40,000 adult sites in Hitwise's database. That's more than twice the number of all online retail sites that we track. One of the things that stands out about the distribution of porn sites is just how fractionalized the spread is. The top 500 sites account for only 56 percent of all visits to the adult category. (In contrast, the top 500 retail sites account for 76 percent of all retail visits.) When taken together, those 40,000 sites accounted for 10 percent of all Internet visits in August 2007, down from 16 percent in August 2005.

While visits to adult sites may be falling, one pattern has held true over the past several years: the days of the week that we are most likely to visit adult sites. By breaking down visit data into daily increments, we find that Friday is consistently the weekly peak, followed closely by Saturday. The day of the year with the least visits is Thanksgiving Day, perhaps due to the number of family members present in the household.

Visits to porn sites on the other weekdays tend to remain constant at 6 percent below the Friday peak. Perhaps the Anglo-Christian tradition that deems it the day of rest explains why Sunday, of all the days of the week, on average registers the smallest number of porn-site visits.

Based on the theory that Internet users would be most likely to view adult content on the days that they're at home and have free time, we would expect that the weekend days, both Saturday and Sunday, would have the highest frequency of adult visits. However, despite declines in church attendance and in the percentage of the U.S. population that identifies itself as religious, the fact that Sunday registers the lowest percentage of Internet visits confirms another theory: In the United States there is still some connection between our religious beliefs and indulging in taboos.

The Sunday statistic probably comes as a pleasant surprise to Mike Foster and Craig Gross, two pastors who annually celebrate Porn Sunday on the first Sunday in October, a tradition they started in 2005. Gross, the founder of xxxchurch.com, which he dubbed the "#1 Christian porn site" (the site is an anti-porn site), tours the country in a tricked out Scion XB. His ministry is a nondenominational religious group focused on eliminating porn addiction. According to Gross, God visited him one morning in the shower and had one word for him: pornography. This in-shower calling started Gross on his mission, which includes attending adult-entertainment trade shows so he can hand out Bibles emblazoned with JESUS LOVES PORN STARS.

So that's the "when" of online porn. Solving the "who" of adult content connoisseurs is a difficult job given the ubiquitous nature of porn consumption. On average, 72.6 percent of visitors are male. Pornographic content in the form of pictures and videos attracts an almost exclusively male audience, conforming to stereotype. However, if you expand your focus to erotic literature, female preference for the written form of adult content becomes clear. For example, the site adultfanfiction.net, the largest of its kind, is predominantly visited by females - 65.5 percent - and its audience is also young: 54.6 percent of them are 18- to 24-year-olds, something that is becoming increasingly atypical in the category.

A regional breakdown of adult-content visitors reveals only a slight skew, with the Midwest Internet user slightly more likely to visit adult sites. The states with users least likely to visit adult sites are the newest states in the union, Hawaii and Alaska. This pattern can change depending on time of year, particularly during winter, when there is a marked increase in porn activity for cold-weather states.

If we break Internet visitors into their red-state and blue-state contingents, and then rank adult sites by their overall use in those states, we find that red-state visitors are likely to check out wife-swapping sites, adult Webcams, adult matchmaking services, and sites devoted to voyeurism, while blue-staters are most likely to visit directories for adult entertainers and escorts.

When we compare visits to the category of social networks to visits to the adult category, the pattern appears to show a negative correlation. Could social networking activity be a substitute for visits to adult sites?

Two days in the summer of 2006 may hold some insight into the trade-off between social networking and porn. On July 22, 2006, a very warm day in Southern California, something went very wrong at 1200 W. 7th St. in Los Angeles, also known as the Garland Building. The building housed the servers for MySpace. The home page for the most popular domain name on the Internet at the time, which accounted for 4 percent of all Internet visits in the United States - more than 17 percent of all pages viewed - displayed a short, casual message from founder Tom Anderson: "Hey, everyone! There's been a power outage in our data center. We're in the process of fixing it right now, so sit tight."

For those two days in July, we examined the rest of the Internet by site and category, looking for unusual increases in market share. We found that Google experienced the greatest increase. There were two other categories that experienced increases during the outage: online dating sites and adult sites.

Another possible explanation for the drop in market share for the adult category lies in the changes in age demographic over time. The percentage of 18- to 24-year-olds who visit the adult category dropped from 15.9 percent at the end of 2006 to 13.4 percent for the same time period in 2007. The same is true for the 25- to 34-year-old age group, which has dropped from 24.1 percent to 18.6 percent. These are the two groups that have also seen dramatic increases in visits to social networking Web sites. All of this data together appears to indicate that there is indeed a trade-off between the two types of sites. Search-term patterns, more specifically the search for sex, further confirm this theory.

If we look back two years, when social networking sites were much smaller than they are today, searches for "sex" went to a variety of sites, including those dedicated to sex education and articles about sex. That same search term now drives traffic to online video sites, Wikipedia and MySpace, indicating that consumption of online adult content has moved from the world of static display of images and video to the world of Web 2.0, where consumer-generated media and social networks play a key role.

In November 2007, I wrote on the subject of social networks versus porn sites in "Science of Search," my weekly online column for Time. Several college students (all, I'm assuming, in the 18-24 demographic) sent me messages through Facebook. Social networks were replacing visits to adult sites, they said, because those networks give young users the ability to connect with other singles in an unprecedented way. To quote one of my newfound young friends, "Who needs porn when Facebook gives you the opportunity to hook up in the flesh?" He may have a point.

From Click, by Bill Tancer. Copyright © 2008 Bill Tancer. Published by Hyperion. Available wherever books are sold. All rights reserved.