The daily interest is a nice thing, but dangerous on a gambling site. I have deposited some money and now I am always very tempted to give gambling another try. I used the Multiply BTC bonus a few times and turned my ~0.14BTC investment in ~0.23 which is nice. But if I continue doing that, I will eventually lose everything, obviously. I consider that smart business (from freebitco.in-perspective) and it should work, the interest is realistic. I would not risk too much money, though. Freebitco.in is in business for a very long time, but that is not a guarantee. There might be a high temptation to just run with all the money. Use your own brain.