The past decade has been tough for newspapers, but many newspaper execs are arguably more upbeat about the future than one might expect.

There may be a need for that optimism, but it might also be completely unfounded if new figures about newspaper revenue in 2011 are any indication.

According to the Pew Research Center, newspapers in the U.S. lost $10 in print advertising revenue for every $1 in online advertising they gained in 2011. That is a statistic that should keep conscientious newspaper executives awake at night. Even more disturbing: things are getting worse, not better. In 2010, every $1 increase in online ad revenue was associated with a $7 decrease in print advertising revenue.

In absolute terms, the industry saw online ad revenue grow by approximately $207m last year while print ad revenue dropped by approximately $2.1bn.

That type of decline, for obvious reasons, is unsustainable.

So what can newspapers do? Embracing paid content appears to be the only thing they think they can do. According to Pew, a much larger number of newspapers are going to roll out digital subscription offerings in 2012 in an effort to become less dependent on advertising overall.

But it’s not clear that this is a panacea. While some newspapers, like The Wall Street Journal and Financial Times, have thriving subscription businesses, others haven’t been as fortunate. The New York Times, for instance, has less than 500,000 paying digital subscribers. Sure, that isn’t a paltry amount, and it may even exeed muted expectations, but it’s hardly enough to maintain the status quo.

For smaller regional newspapers and those that aren’t in lucrative niches like finance, digital subscriptions are almost certainly not going to provide enough revenue to support the kind of newsgathering organizations that these entities were able to afford when times were good. Which leaves one option: further cost cutting.

An obvious way to reduce costs is to cut print. In fact, Pew’s study notes “A growing number of executives predict that in five years many newspapers will offer a print home-delivered newspaper only on Sunday.”

The irony, of course, is that by cutting print, newspapers assure themselves less print ad revenue, suggesting that the ratio of print ad losses to digital ad gains is likely to widen in the coming years. For many newspapers, that means one thing: game over.