Cowen and Company analyst Doug Cruetz reports most major social titles from Zynga, Electronic Arts, and Disney/Playdom have suffered double-digit declines in the month of August.
This follows months of speculation that poor mobile strategy has been taking a toll on major social games publishers like Zynga.
"We believe that over the last several months, trends in the casual digital gaming space have swung decisively towards mobile and away from PC-based social gaming, at least in Western markets," Cowen told Gamasutra.
As gamers migrate from traditionally free-to-play desktop platforms like Facebook there is an increasing prevalence of the business model on mobile markets.
Of the 60 titles that form the top 20 most grossing games for August on iPhone, iPad, and Android, 56 were free to play.
The migration is drawing developers away from social markets as well; Zynga famously spent $210 million to acquire OMGPOP - makers of the mobile sensation Draw Something.
Even Facebook CEO and founder Mark Zuckerberg concedes the primacy of mobile games.
"A lot of the development and the energy in the eco-system is not going towards building desktop stuff anymore, it's going towards building mobile stuff," he said.
"We're able to integrate and we're helping a lot of folks build great mobile experiences - that's the future."