The number of people reading digital magazines has doubled, though the medium still counts for just a small fraction of the overall publishing business. According to a report from the Audit Bureau of Circulations, as reported by Ad Age, digital circulation jumped to 3.29 million in the second half of last year, up from 1.46 million during the previous six months. But while the numbers are growing, they currently account for just one percent of overall magazine sales. In spite of this, the relatively rapid growth of the platform seems to have publishers excited. For instance, Hearst Magazines, publisher of titles like O: The Oprah Magazine and Esquire, expects to see its monthly digital circulation to top one million readers by the end of 2012. And with digital magazines being made available on an increasing number of platforms, those numbers should only continue to grow.