Your general computer USB port will charge at 0.5A, meaning devices will be slow to fill and often larger products like iPad's will either refuse to charge or never raise a percent in battery level. According to Andy & Rich, one useful example is the fact that their device will effectively enhance your charging speed from a general Macbook to iPhone from 0.46A to 1.1A without any drivers, software or optional extra's plugged in. The device can also be used for wall-USB chargers, seeing iPad's which previously refuse to charge accept the power being given.
The cable also blocks data transfer when wanted, meaning that this tangle-free braided cable will see your data stay safe and device continue virus free.
If you're interested in providing support, an $11 investment will secure you one cable for your own use.