I was in the top three for a keyword with my 8 month old site with pleanty of links. There was virtually no competition and no google PPC Now there is plenty of PPC and my site is falling The PPC activity has tripped the sandbox effect for the keyword. I really don't think it is down to links etc or competitive sites. The filter has flicked on and I am dropping. Hope this gives some of you a deeper insight into the sandbox filter.