HTC's market challenges have seen it lose more than half of its share of online usage, Chitika found in a new study. Its traffic on Chitika's relatively large ad network has dropped 60 percent in the space of five months, down to 7.3 percent of the total in March. While only representative of Chitika's share, it contrasted with Apple's gain in the same space of time, where it leapt from 46.8 percent in October to 76.9 percent in March.