I have a site (actual several) that has been up for many years now. Content is changed monthly - regularly. It would always rank in the top 5 positions for 5 or 6 keywords. Now all of a sudden (without any dramatic changes to the website) my ranking results from my weekly Moz reports are dramatically different from week to week - every week. One Keyword will be #1, then the next week it will drop 49 positions, the 3rd week it might be #5, then Not in the Top 50, then #1 again, and so and so on. This happens to all my keywords on my site. I was waiting for Google to finish it's changes to it's algorithms but it's now been long enough and I can't get a handle on what's happening, why it's happening, and what to do about it, and what direction to take with my SEO. My Traffic has actually improved over last year by approx. 25%, but I have also started a PPC campaign for this client. Any suggestions would be great.