During this last update/shuffle/whatever, one of my competitors moved up significantly for nearly every phrase I've been tracking. They've moved ahead of me on some, and moved ahead of some sites that were solidly #3 or so.
In looking at what they've been doing, two things jump out at me immediately: freshness and links.
I spoke with the manager of this business last year, and congratulated him on his rising rankings. He muttered something about putting up stuff every day, then changed the subject. I thought of this comment yesterday and did an advanced search using the site: operator. When I selected results from the last 24 hours, I found that they're uploading 30-50 modified pages every day. I've kept archive versions of pages, and I find that the pages are modified only slightly. For example, they have a special offer for a blue widget one day, and a special offer for a red widget the next.
I've always been of the "if it ain't broke don't fix it" mindset, and so have not altered pages that rank well unless it's necessary.
I'm looking at other factors that may or may not be helping them, but this one has me wondering.
I'd be curious to know what others here think about my possibly flawed mindset and what my competitor is doing.