gzoo - 10:47 am on May 13, 2012 (gmt 0)
Thanks jemois & deadsea for your contribution.
@ jemois, my website is approx. 3 years old. Website doesn't seems blacklisted and neither it is get penalized ever in past.
All sub-domains are new but the data is old and yes I have applied 301 to move old URLs to new one. Initially Google crawling was good on main website as well as on top sub-domains for approx. 6-7 days but later on (since last 4-5 days) suddenly it gets dropped up to 90%, means ratio dropped from 100 to just 10-12.
Using "site:" I can see good number of index pages of top sub-domains but I can't say that all pages are indexed.
One problem I just noticed in WMT is increased number of not found or 404 pages, while reviewing those pages I found that to increased the search quality we tighten the criteria of landing pages which result in generating "0" results pages which are reporting as not found or 404. Could this be the reason of this issue?
I would appreciate the contribution of experts in this thread?