Dive Brief: 

• Popular adult site PornHub is steadily gaining more mainstream advertising, such as Relativity Media's 30-second pre-roll videos for the new film "Don Jon."
• Brands are drawn to adult sites often because the cost of advertising is significantly lower than most mainstream sites—campaigns are as much as 90% cheaper than sites like Facebook, Twitter and Google. 
• As PornHub's vice president points out, the traffic on adult sites is also much of the same demographics as more mainstream sites. 

Dive Insight: 

For smaller and more progressive companies, advertising on adult sites makes sense. The traffic is high, the cost is low and they reach a similar audience to more acceptable mainstream sites. Many brands may never be able to associate themselves with the adult content, but as long as sites like PornHub remain popular, more mainstream advertisers are likely to test the waters.