I created a new domain in June 14, in August/Sept I created a PBN and the site ranked in top 3, in Feb/March 15, I noticed an old business associate had created a rival site and targeting the same keywords! So I started building tier 2 & 3 links to the PBN using socialadr and followlike (Facebook/Twitter/Google+), now the home page has fallen off google (not in top 10 pages after being at #3 spot for months!!!!! All other sites in PBN still ranking strong, no issues. Inner page still on page 1 - home page still indexed in google. I am checking using serpbook and discovered this yesterday. All content unique and of quality - not spun! Any ideas what could have gone wrong? Is it google dancing?? What can I do to come back?? Thanks.