Last July, one of my hobby sites that had been enjoying great traffic for years (since late 1999) suddenly saw a huge dropoff. Previously to that day, the site had had roughly 4000 pages in the top 10 (mostly #1's) for the relevant phrases on google, but all dropped back to the 4th-5th page.
A little digging revealed that a search for "www.mydomain.com" showed our domain on the 4th-5th page as well. (all our other sites come up #1 for that search).
A little tech info about the site:
1. It's on a dedicated server (had to, because the forums were killing the shared hosting account).
2. It's been redirecting non-www to www URLs via .htaccess since 2002 (based on advice received here)
3. PR has remained at 6, and all pages appear to be indexed (can't find many supplementals). Although the "site:www.mydomain.com" command returns roughly 3 times the number of pages we have.
4. Aside from using tried-and-true html standards (pages validate), we've never really SEO'd the site (like I said - just a hobby site).
5. Site's been using adsense to support it almost since it was released to the public.
6. Inbound links have actually increased since last July (all one-way). To include links from the Wall Street Journal & Fast Company, among others.
7. 95% of content is original (we do post some relevant press releases from time to time). New content is added daily (5-10 pages of articles) as well as at least 70-100 pages of forum posts (all of which eventually get crawled).
So.....now that you know all that, my question is...what could be causing the site to come up on the 4th-5th page for a "www.mydomain.com" search (which seems to be a symptom of what's hurting the site as a whole). We still enjoy good traffic from Yahoo/MSN, and receive some traffic from google (but only a shadow of it's former volume), and have never participated in reciprocal linking.
Is it a penalty of some kind? A technical glitch? Something that will eventually work itself out?