There have been recent posts about the impact of individual site quality having impact over a portfolio of sites if they are associated, in this case via a master WMT tools account. I am concerned that I am not following best practices if this is the case. I am currently managing over 200 client sites, they each have there own unique GA account to which I am added as an administrator. I have verified these sites in WMT using the GA verification method.
With the various updates throughout the year individual sites have been impacted by Panda and Penguin, which have been addressed and rankings reasonably recovered. However, since November 22 however the entire portfolio is off over 20% with some having lost over 50% of their historical traffic. I am concerned that the better performing sites are being impacted by the weaker sites as a result of their association in a master WMT account.
Keep in mind, many of these site were transferred from other hosting providers with existing issues. Content is driven by the client and my impact is dependent on client effort which is minimal. So apart from standard SEO strategies and building value driven backlinks doing specific site based changes is restricted. Could their association be causing the drop in performance. If so, why would this be happening in reverse, the weaker sites improve?
Thank you in advance for any advice or input