A rare visit to [200 OK] from the marketing department (the programmers usually try to keep me far away from their beloved blog!)...
If you're involved in the SEO end of your Web site, you're probably already aware that Google recently made some major tweaks to PageRank (their rating of Web site "relevance" based on the quantity & quality of inbound links). We were a little dismayed to show up to work a couple weeks ago and notice that Google had slapped the dreaded PR0 on http://www.port80software.com/.
Does that mean our site isn't relevant?
Does it mean we have no good inbound links?
Does it mean we've been blacklisted or not spidered?
Afer some research, the answer on all three counts is "No". It's my job to make sure we've got a pretty solid collection of backlinks, and we're still showing up OK in Google search. In fact, the answer has at least something to do with content negotiation...
If instead of entering http://www.port80software.com/ you enter http://www.port80software.com/index (which is, of course, where the server actually points to) PageRank returns to normal!
There's no doubt that a lot of sites did see their PageRank drop incrementally with Google's last update. But the fact that, despite our apparent PR0, we still show up about where we used to in Google searches indicates that Google's "real" PageRank algorithm (see below) may be smart enough to see through most server-side redirects and URLs rewritten by content negotiation.
A couple related things I learned in my research:
1. The PageRank score in the Google toolbar may or may not reflect your actual PageRank in Google search, at the very least it's an approximate score and should be taken with a grain of salt.
2. Google's backlinks count (search for link:www.domain.com) is also notoriously unreliable -- I had several people say that Yahoo! backlink searches tend to be more representative, though they're harder to do.