I just started using a similar site. It's called Richmond Berks. They claim to use your investment to buy real estate for cheap and resell it but there is a lot of reviews that say it's a scam. Although, nobody actually says they tried it and it didn't work. They just can't find much information on the company. I did the same as you, put a small amount in to see what happens. It turns out, they are actually paying me at least 1.5% a day just like they claim. I've already made about $8 since the start of the month (which I have already cashed out to bitcoin). I wouldn't be putting thousands of dollars in there but maybe I'll re-investing some of the profit until I see a big enough return to buy a coffee every day.
RE: Bitcoin Ponzi Scheme: BitZilla