Hissingsid - 10:59 am on May 29, 2012 (gmt 0)
Is the fact that they are directories just a co-incidence. Could it be same anchor text from 500 sites regardless of what sort of sites they are?
Could it be a combination of this, KW packed description meta and sitewide anchor text all just adding up to over optimisation.
I was interested to see that a site with no meta description or KW is doing well despite having bought links from a directory network.