From PR4 to PR1 - What does this mean?

[palmpal]

Hi All,

I just discovered that my website dropped from PR4 to PR1! I've been online since 2002. Google had always been my highest referrer but a few months ago Yahoo took over that spot. Recently I noticed my Google referrals increasing.

I get really good results in the search engine results for my key words. Is the PR1 something I should worry about? What would you look at first?

I've never been able to get higher than a PR4 and wondered what drives PR the most.

Thanks

[Teknorat]

PR doesn't mean jack. SERPS are the only true measure. My PageRank has been fluctuating almost hourly today.