The ROI is very reasonable for monthly gains. If it is a scam, it was designed very well to fly under the radar and not cater to greed. However, it does take Bitcoin's name instead of trying to make its own, and that speaks for a lack of confidence by its founders. If it gets mass adoption, it can be valuable for awhile, until people get bored and move onto the next thing. I wouldn't drop a dime into it.