Originally Posted by Cucik

I have small adult tube, it's two years old, it was among top 10 on Google and it was hit by some Google algorithm last year. I wanted to let domain expire, but six months ago it was on position 2 again. I didn't build more links and I didn't add new content.

But, after two months, it vanished again. I have a site on Webmaster tools and it doesn't have manual penalty.

How can I find out why site lost its rankings?