I have a site that has been up for about 10 months now and ranking #1 for it's main keyword for the past 5 months. I haven't done any other backlinking or touched the site. The content on the site is unique. So today I searched for the main keyword and the site is gone from the SERPs. Not only no longer #1, but when I do a "site:mydomain" the home page no longer comes up. Only the internal pages get listed. Anyone know if this is a temporary glitch or what? Should I be concerned at all? I've seen this before when I put a new site where the home page get's indexed and then goes out of index for a few days, but comes back. But this is weird since this is a established site now and I didn't do any sort of backlink blasts either. Any feedback?