My keyword SERP positions seem to change a lot. My main keywords are pretty stagnant around 8-12 and don't change often. Then I have some secondaries that jump around from 5-25 every few days. And lastly I have a couple of keywords that jump from the 50s to 150s then back to 50s every day. I also have some that aren't on the top 200, or just made it on the list. I'm not sure what needs to be done to keep them from changing so often. Also, what can I do to start raising their SERP rankings to the 1-10 positions?