Robin Good: If you have been submitting your blog, web site or RSS feed indiscriminately to tens of web directories, you may want to give a serious read to this report from SEOMoz.
According to the research done, Goolge has started banning and penalizing many web directories as many of these offer next to no value at all to final readers, and have been created mostly with the purpose of providing a promotional/visibility/linkback resource.
It looks like Google has decided to stop allowing these sites to pass "juice" to its listed member sites by penalizing them and in the worst cases (tens of them) to completely ban the directory from the SERPs.
From the SEOMoz original article: "...Google deindexed several directories a few weeks ago.
This event left us wondering if there was a rhyme to their reason. So we decided to do some intensive data collection of our own and try to figure out what was really going on.
We gathered a total of 2,678 directories from lists like Val Web Design, SEOTIPSY.com, SEOmoz's own directory list (just the web directories were used), and a few others, the search for clues began.
Out of the 2,678 directories, only 94 were banned – not too shabby.
However, there were 417 additional directories that had avoided being banned, but had been penalized."
Very useful data. 8/10