I'm currently running a voucher/coupon site. Started work on it 3 months back. Over that time, I have added a good deal of original content, and done some heavy backlink building, blackhat style. I have been taking care to keep the rate of link building consistent, with a steady rise and stable plateau - the links point to the sub-pages with relevant anchor text from high PR ******** sites. A few days back, I began to rank very well, hitting the top spot in many cases for my sub page target keywords. As of 11am today, most of the sub pages are struggling to reach page 10. :chairshot I would suspect a penalty, but my home domain is still number 1 for its name, and variants of its name. I've had penalties before on other sites - in each case, the home domain was severely affected in the rankings. I have not received a manual visit from any of Google's review centres. Does anyone have an opinion as to what has happened - and whether I can expect a recovery if I maintain consistent link building? I have a theory that the drop is part of google's automated test to see if the link building remains consistent.