I actually invested in it earlier today.
It may be silly to do so in terms of profit, as I won't be making no huge leaps and bounds every couple days day-trading or simple luck but it's a low-risk investment, has decent returns, and adds to that all important diversification.
You may say "NO(!) I have those crypto-currencies in coin-form" but adding a consistent stream of them improves diversification as you are now covered more from potential slow-downs and stabilization of the currency, as well as you have less stress to actively exploit your wallet as your mining rig is doing it for you.

You may not need it, you may be able to do better, but the bottom line is GM is profitable and is extremely low-risk.
If you use GM make sure to use a referral code to get a discount as well, as it'll take many days off your ROI. If you want mine, I'll provide it, or go to reddit or the like and try to find someone else to match it if you wish. Just get yourself a code and preferably by someone who's content you enjoy.