Apparently, those young’uns just love their BBM. According to a report by the research group Mobile Youth, young folk (read: those of you between 15 and 24) are increasingly abandoning SMS in favor of instant messaging apps, with texting expected to drop off 20 percent over the next two years. The main culprit? BlackBerry Messenger, which now boasts over 39 million users, many of them living outside the US. In fact, it’s in the UK, Indonesia, South Africa, and Brazil — all popular markets for BBM — that Mobile Youth expects texting to dwindle the most. And if BBM is to blame, well, that drop-off could be just the beginning.