It's not interest is address empty or not.

Because website like this sending from cold wallet I think. For example. I'm investing to globalbitcoindoubler.com and they're sending to me from different address everyday. But these address include just my profit mostly. And They're sending daily, so  I can cashback daily my profit. If there are pending, it's scam. But I trusted globalbitcoindoubler.com

But If I can say as negative for this site, I hasn't refferal system.