Blackhat SEO works. Not for very long, and it's plain wrong to do, but some (if not all) of those optimization tactics have given top SERPs and traffic to websites. And when you get caught by the SEs, your penalties will be very harsh. Delistings and such! So besides purposely using blackhat, what have been some of your honest mistakes you've made in SEO, that you want to share with the rest of us? As we better learn from mistakes than success!