In a report issued jointly with domain registrar VeriSign, comScore said 4 percent of all web traffic and two percent of all surfing time involved an adult site.
Nearly 71 million web users visited adult sites in April, down around 3 million compared to April 2004.
Surfers during the same month logged around 6.3 billion minutes looking at adult content, dropping 1.3 billion from the previous year. These users generated 17.7 billion page views, almost 1 billion less than last April’s views.
However, some critics say numbers from companies such as comScore should be looked at with a touch of skepticism.
Historically, it has been difficult to find reliable statistics on adult website usage since many tracking services don’t include adult sites in their reports.
“Although it’s now a good five years since web surfing went mainstream, there is still no credible way of measuring a site’s popularity that advertisers and media analysts can turn to,” IDG analyst Chris Keall said. “There isn’t even a vague consensus about how traffic should be measured.”
One site attempting to provide objective web rankings is Alexa Web Information Service, which tracks site visits on a daily basis.
According to today’s Alexa rankings, NastyDollars is currently the only adult-oriented site to crack the top 100 English-language sites, holding down the No. 66 spot.