You can thank smartphones, the iPhone and touchscreens for heating up the accessory sales sector. This year, sales of mobile phone accessories are expected to top $40 billion in revenue, according to ABI Research. The research firm also expects this year to be the beginning of steady revenue growth curve, ultimately generating more than $80 billion by 2012.

Not exactly chicken feed for the often under-appreciated sales segment. Because handset makers and mobile operators are selling more feature-rich devices, they recognize they also need to supply more accessories. And these accessories extend beyond the traditional handset cases, batteries and chargers to include headsets, memory cards and data connection kits.

“More people buying expensive smartphones and feature-rich devices mean greater demand for accessories that protect handsets, and also for accessories that enable the use of different features and applications on the handsets,” said Shailendra Pandey, ABI’s industry analyst.

The accessory line is growing more diverse and expansive, according to Pandey. The popularity of large screens and touchscreens on wireless devices is driving strong sales of products that offer handset protection, such as cases, covers, screen protectors and scratch removers. Audio-video playback capabilities in handsets are resulting in growing demand for earphones and headsets, as well as memory cards to enable storage of music, videos and images. Also, the need for connecting the mobile phone to the PC/laptop for transferring multimedia and data files means a greater need for accessory products such as data connection kits and USB chargers.