I am surprised to see a 80% decrease in no. indexed pages for my site in Google.com ( i have used link:xyz.com). Although in yahoo, no of indexed remain s same (linkdomain command). Interestingly, my competitors are also facing the same problem? I am running a very popular site with PR7 and site links. NB. SiteMap already exists. What could be the reason? Is Google changing its algorithm ?
Google is changing the way the link: tool works and I've noticed some odd things in the index as well, I think we just should wait it out and let things settle down....
Do you mean the number of backlinks? You can log into your sitemap account and check for the number of links now
I think fsmedia is right, after going through this article in google official blog it seems they are discounting reciprocal link exchange; http://googlewebmastercentral.blogspot.com/2006/12/building-link-based-popularity.html