Netflix is poised to become the largest subscription entertainment business in the U.S. when it reports quarterly earnings on Monday. Analysts are figuring that Netflix will have added around 3.7 million subscribers to its ranks, giving it 23.7 million, give or take 100,000. Even if Netflix is shy of estimates, it will likely show enough growth to propel it ahead of Comcast at 22.8 million video subscribers and beyond the 20.2 million subs at Sirius XM Radi o. Because growth has stalled at Comcast’s video business, it will likely have to settle for being third in this particular contest as Sirius XM and Netflix duke it out for supremacy in the entertainment-subscription arena. Ensuring that Netflix maintains it’s growth – and some analysts predict it will close out the year with north of 30 million subs – is its embrace of digital streaming, where there isn’t much competition yet. Analysis from NPD, in fact, suggests 61 percent of all movies viewed through the Internet are d