The threat freemium poses to what the video game industry now refers to as “physical media” has become so worrisome that traditional publishers like Ubisoft Entertainment SA (EPA:UBI) and Electronic Arts Inc. (Nasdaq:EA) have begun to introduce their own lineups of free-to-play titles either to complement their current games or to replace them entirely. Still, despite its successes, the freemium model has had its own share of problems lately. After an impressive period of growth as a startup, Zynga went public last December and its shares have spent the last three months some 70 percent below the IPO price. And in the wake of a weak quarterly earnings report in July, the company has offered a confused strategic vision, saying that it would move away from its Facebook games, which have accounted for 80 percent of its sales, to focus on mobile games and gambling. Top executive talent, including managers of creative and marketing, have been leaving.