Blame it on the economy, or simply chalk it up to a better way of earning revenue, but physical distributors of new video games are beginning to feel some major heat from the scrappy competition. While this mainstay segment still comprises the bulk of sales with $1.44 billion earned in the previous quarter, the combination of digital purchases, subscriptions, downloadable content, social network and mobile games -- along with help from rentals and used purchases -- now tops $1.74 billion dollars. This news comes from the NPD Group, and while w