It is not unusual for a new page on your website, or for that matter a new website to place, well initially in the organic search results and then drop in placement over time. Why?
Matt Cutts at Google explains why there are fluctuations in organic placement on Google.com in this video found on YouTube http://youtu.be/BzfK6isC7CA.
Here’s a synopsis:
- As Google spiders the Web, it may find similar content knocking down your placement.
- New content may be created over time that is more recent and knocks down your placement.
- Google initially boosts the page and then drops it if over time it does not garner backlinks.
- Google is initially guessing where a page should place and then understands later due to links and co-citation if the page should continue to stay highly placed.