For the past five weeks I've been tracking an interesting trend in my stats for the highest trafficked page on my site: Google returns this page at #2 in its results for 7 days, then removes it COMPLETELY from results for 7 days, then returns it again at #2 for 7 days, etc. It's like clockwork, on the 7th day, I can count on the same change. The only caveat is that it seems that Google is only removing the result every other week from US results; international Google sites (non-.com ending) continue to return the page every week. Is anyone familiar with what might be happening here, or has anyone had this same thing happen to them?
Here is a possibility as to what might be going on... People often notice fluctuations like the one you have described. It is sometimes referred to as the "Google Dance". The thought is that Google is testing your page out in various positions in the SERP to figure out where it fits best and creates the best results for searchers. You should worry little about the dance. Instead focus on link building, on page optimization, and continued learning of SEO. Remember the dance represents a short term fluctuation and SEO is a marathon, not a sprint.
When a current event pops up on the internet (election results, haiti earthquate etc etc), it pops up in Google very quickly, so that Google can, well, stay current with the current events. After the first wave of interest passes, Google gives it a more permanent position in it's index. This = Google dance. It's normal.