Drop in Rankings on Google UK

[jane]

Rankings of my primary keywords of one of the site going down continuosly since 3 days, whereas i have 3 more sites in the same area which are either stable or moving up. All the On Page done and off page is also in progress, this is affecting the sales of this particular site. What could be the reason of this sudden drop? Checked WMT no error reported so far.

[aristotle]

Without more information about your site, it's hard for anyone to give a definite answer. I suggest that you read some of the other active threads here where various possibilities are being discussed. Also, check your indexed URls and crawl access in WMT, also robots.txt, and server files for possible hack.