A: To connect more devices, because your life is not complicated enough already.
Q: How many USB 3.0 Hubs can I connect in total?
A: As many as you can cram into your desk, but not too many, because that's just not safe.
Q: Can I use a USB 3.0 Hub with my 2.0 devices?
A: Only if you enjoy the thrill of possibly frying your motherboard, but we don't recommend that.
Q: Are USB 3.0 Hubs safe for my precious cat?
A: No. Your cat is not a device. Please don't try to charge it through a USB port.
Would you like to know more about care and maintenance of your USB 3.0 Hub?
Or perhaps the electric shock hazards associated with USB Hubs?