Shares of Zynga (ZNGA -3.3%) give back some ground after tacking on a 15% gain over the last...

|About: Zynga (ZNGA)|By:, SA News Editor

Shares of Zynga (ZNGA -3.3%) give back some ground after tacking on a 15% gain over the last week. A report out today from Cowen questions the valuation model on the stock based on the high churn rate of game players: "Assuming Zynga averages a 20% quarterly rate of decline for titles beyond their launch windows in 2012, the company must add 9-10MM DAUs per quarter from new games just to keep total DAUs constant."