Hidden Chronicles' 12 day post-launch DAU total of 710,000 is well below the over 5 million DAU figure reached by Empires and Allies and Castleville during their first 12 days of existence; similarly, Scramble With Friends has failed to penetrate the Top 20 barrier on the App Store. Historically, Zynga's DAU totals peak 3 months after a game has been released (according to the report), and while it's possible that both Hidden Chronicles and Scramble With Friends could slowly acquire a larger user base, there's nothing in Zynga's statistical history to make that extremely plausible.
Now, 710,000 daily users sounds like a ton of people, but Zynga has set the bar so high that it's not enough to keep the company's overall growth even: "The quarterly rate of DAU decline for Zynga's titles that are at least three months old has averaged 18.4 percent per quarter for the last two years," explained Doug Creutz of Cowen and Company. "Assuming Zynga averages a 20 percent quarterly rate of decline for titles beyond their launch windows in 2012, the company must add 9-10 million DAUs per quarter from new games just to keep total DAUs constant."
So basically, any game Zynga releases in 2012 has to achieve at least 5 million daily users in order for the company's user base to break even. In other news, Zynga has constructed a super-sonic ultra-high-altitude aircraft to recover the bar it's accidentally set for itself in the exosphere.