A curious phenomenon is happening in the digital subscription world, particularly for newspapers.The Financial Times and The New York Times both reported a growth in digital subscriptions this year, but both also saw some plateaus in profits.Specifically, in 2013, FT’s digital subscribers have grown to a little shy of 400,000, making up 2/3rds of their entire circulation. Yet, revenues were up only 4% in 2012, and there doesn’t look like there will be much growth this year.Similarly, The New York Times hit 727,000 subscribers this quarter, up 28,000 in three months. And in Q3, “digital subscriptions brought in $37.7 million, while digital ads brought just $32.9 million,” reported the Columbia Journalism Review (CJR).PaidContent interpreted these stats to mean that NYT is running to stand still, but that’s not an entirely fair depiction.Legacy publications are going to go through growing pains as they adopt sustainable digital models. They shouldn’t be too concerned with stagnant revenues for a year (or three) as consumer attitudes and business models shift.What they *absolutely* should be concerned about is retention. As the CJR article rightly observed, The Times is not likely to see the exponential growth in subscribers it did during the first two years of introducing the paywall. So now The Times’ biggest task will be to reduce churn and increase retention rates, especially as sponsor-supported subscribers come up for renewal.Luckily, we have a few resources below that can help.