ABI Research (www.abiresearch.com) forecasts global revenues of aftermarket mobile accessories to top $110 billion in 2021. Aftermarket Bluetooth headsets for smartphones will grow the fastest, in terms of both revenue and shipments, with shipments expected to show a 9% compound annual growth rate between 2016 and 2020, per the research group.

"Bluetooth stereo headset shipments are rising steadily, and Apple's rumored decision to remove the headphone jack from its new iPhone only further supports our belief that mobile accessory manufacturers will largely focus on Bluetooth audio listening in the near future," says Marina Lu, Senior Analyst at ABI Research. "Wired headsets are also showing strong growth, as consumers usually have to buy additional headsets for their smartphones."

Screen protectors, protective cases, and chargers also contribute to growth in aftermarket mobile accessories. Apart from larger touchscreens and higher value smartphones, advanced functionality for screen protectors, including privacy protection, anti-glare, anti-fingerprint, anti-scratch, and higher transmittance, is driving their demand. Vendors also cater to consumers' desires to personalize their smartphones by developing well-designed protective cases. And new features built-in to these cases, such as wireless charging, memory expansion, and shock-resistant technology, increase their appeal.

While screen protectors and cases are working in harmony to propel aftermarket revenues forward, wireless charging pads are also powering this year's sales. ABI Research expects them to become much more prevalent over the next five years.

"Specifically, emergency charger shipments are taking off, as consumers' dependence on mobile phones is leading to quicker power consumptions and the need for more frequent charging at different locations," concludes Lu. "Given users' attachment to their smartphones and their wants and needs to personalize and protect them, the aftermarket mobile accessories market is showing no signs of slowing down."