Wearable device shipments are expected to grow by triple-digit percentages this year; International Data Corporation projected the number of wearable device units shipped worldwide in 2014 would total 19.2 billion units—a more than 200% increase. Yet enthusiasm is tempered by two factors. First, significant growth is not surprising in a new tech category, especially one that encompasses a large swath of device types. Essentially, there is a wearable for every major body part. Second, the “magic” product—one that attracts a majority of consumers—has yet to come to market. Many suspect that Apple Watch will be that product when it launches in early 2015. But at this point, penetration among US consumers is low across all subcategories of wearables. Read the rest at eMarketer.