For the last few weeks every 3 - 4 days my clients site goes from #4 on google right down to #36. Then after a few days it shoots back up to number #3 but today its back down to #36.
There isn't anything untoward on Google Webmaster Tools, no Duplicate content or anything like that. The Page Auth is 26 whilst not great our top competitor is only 33.
Do you have any ideas what could be causing this?
Search terms is 'plus size lingerie'