Activision Blizzard's latest financial earnings reveal that revenue from the company's key intellectual properties, World of Warcraft and Call of Duty have shrunk, while revenues from Skylanders: Spyro's Adventure have grown.

Company-wide, revenues for the first six months of 2012 fell by 6.8 percent to €1.731 billion; during the same period in 2011, revenue stood at €1.857 billion. However, despite the overall decline, quarterly sales showed improvement over last year; Q2 2012 revenues rose €41 million, bringing in €837 million compared to €796 million in Q2 2011.

"[R]evenues related to Call of Duty digital offerings and catalogue were lowered compared to the same period last year," Blizzard said. The market seems to be thinking that Call of Duty is peaking: sales numbers could be compared to DICE's Battlefield 3 first-person shooter.

Although Diablo 3 is Blizzard's fastest-selling PC game ever, the full force of its sales have not been felt as revenues "have been heavily deferred in line with regulations on online income" GamesIndustry.biz reported. Activision Blizzard is estimating revenues of €800 million -- up from €750 million for 2012.

World of Warcraft's revenue likely decreased due to lower subscription rates and "catalogue sales": subscribers fell from twelve million to nine million since 2010. The Mists of Pandaria expansion for Blizzard's flagship MMORPG will be released in September and is expected to fuel sales. The release of Guild Wars 2, with its no-subscription business model, could draw subscribers away from World of Warcraft, but for now, World of Warcraft remains the most popular MMOG on the market despite being released seven years ago in 2006.