The past two backlinks updates my sites have not increased in ranking by more than a couple of places, some even went down. I checked through the backlinks of my competitors (on Yahoo and Google) to see if they had simply been working harder than me. Shockingly I found that in terms of backlinks and anchor text my site had the "better" quality, variance and quantity. I built a database of around 4,000 keywords and developed different sites with different optimization techniques to try and narrow down the on-page factors that work well on Google and was shocked at which one actually did well.
Indeed, within 24 hours of some of the pages being indexed they were ranking in the top 10. They were actually beating my sites that had been around for 2-3 years with loads of backlinks and unique, quality content. The 4,000 pages that were generated for that particular site do not provide actual "content" (i.e. information on that keyword) and are just doorway pages using several affiliates search boxes, contextual advertising etc. to generate revenue from people searching for that particular keyword/phrase.
Obviously many believe this instant high ranking is a result of the dreaded "sandbox" and that I will only hold these places for 2-4 weeks. I'll let you know .... but in my opinion these pages should not have been ranked that high in the first place and the filters that must be in place for these pages to have ranked is just unbelievable! If they were trying to filter out spam they missed the mark and hit the genuine sites instead.