
I invested some spare bitcoins that I had from mining and so far it is going realy good. Minimum ammount to invest is 1mBTC or as I cound 0.001 BTC.
In any case, if you choose to invest remember one thing. NEVER invest more, than you can afford to loose. Any investment no matter where - is a risk, be it stocks or a bank or any other. So the rule applies anywhere.
This proved to be a nice service provider. Although I was sceptic about it, but still I tried and so far I have made about 30% of my money invested.