Geeks always want more and more from their devices. Even their device has limited features they still want more. USB OTG is another thing which is made for geeks.
A useful mean:
OTG allows you to attach several USB peripherals into your device through micro USB to full-size USB adapter. The basic idea is to use more input devices than a just touchscreen and limited on board storage. Suppose you are on a tight budget and you are thinking to buy a smartphone with nonexpendable storage then an OTG can save you a couple of bucks, just plug in a regular USB thumb drive and store whatever you want in it. You can use it right away anywhere. So by this way you can carry many USB drives according to your file needs.
Now let me tell a more spectacular story, there are a couple of devices in the market that allows you to connect an external hard drive into your smartphone that makes it so astonishing. Which enables you to use a high amount of data anytime. Having OTG support means that you are more secure as you can store your confidential/sensitive data material into an external USB stick which prevents from misuse of it. You can also backup your entire phone apps and settings through Titanium backup (device must be rooted) and store the image file into a USB stick to prevent data corruption or data loss.
OTG is not a new thing, its specification was first used in late 2001. But they became more popular with the smartphone era, Nokia’s N8, C6-01, C7, Oro, E6, E7, X7, 603, 701 and 808 Preview were one of the first generation devices to have this functionality on their device. Later Blackberry also came up with this on their Blackberry 10.2 OS. In Android, it was first introduced with the Honeycomb 3.0 OS. later all the newer versions got this functionality. An adapter is required to attach USB peripherals to the devices.
Conclusion and possibilities:
The story is not just limited to storage options (USB and hard drives) there are different aspects as well. Using physical keyboard and mouse with OTG cable is also possible. I know using a mouse and keyboard as input devices with smartphones is not an intelligent thing. But think about the tablets.Everyone admits the fact that they like to type on physical keyboards rather than on touch screen. In tablets attaching keyboard and mouse gives you more precision on work and offers better reliability. It creates a desktop like an experience on the tablet. Gaming with joysticks is also possible with smartphones, you can connect various gamepads to the devices through OTG cable.
A regular Xbox 360 joystick suits the best to most of the devices although you can connect PlayStation joystick and others also. Joysticks provide better control than ordinary touch screen based control. It’s just like a car with an automatic gearbox and a car with a manual gearbox, the user will always have more precision with manual gear box. Similarly, Joysticks gives you more clicky, tactile feel over the touchscreen. Most of the high-end games are compatible with joysticks and work at their best with them.
Hence having an OTG functionality over your device is a big plus point to the user. More functionality makes the devices cooler.