Case study: what happen to this site ?

Referring pages drop but referring domain skyrocket....

What is happening here I guess Panda 3 and spam

rapidly building links and losing links. Later strategy seems to make less links per domain . ?

No I find it:

The guy don't know whit about Seo, so he don't build link at all.

He's website got a forum.

This forum use to have a subforum to redirect the spam because he did not know what to do.

Then he delete this subforum (So the huge decrepency in referring page).

Weak management...