I just started getting into digital sales on PSN and I purchased The Last of Us about 14 days ago. Sony just dropped the price to 44.99 from 59.99. In my experience with retail outlets is that if you purchase a game and the price drops within 15-30 days (depending on retailer) one could get the price difference. Sony offers none of that in the digital world so as far as I'm concerned I'm done buying stuff from their digital store and will continue to purchase from actual stores. Just seems a bit stupid that they can't offer refunds for up to a certain time period like most places do. Not exactly sure how MS handles these situations, but if its similar to Sony I wont be touching the next gen digital stores for anything more than a couple of dollars.
By the way it isn't a promotion, but a permanent price drop.