Advertising agencies have begun to devise strategies to deliver marketing messages to consumers via the burgeoning wearable technology market. The accompanying infographic shows how sales of wearable devices are expected to explode over the next few years with a projection of as much as a tenfold increase.

According to Businessweek, there are, however, some concerns that may stifle advertising revenues. User privacy has become more and more of an issue lately. Bryan Yeager, an analyst at EMarketer Inc., says that privacy is “something that they have to consider when they’re building these applications — how far is too far?”