I start discussion some time ago that Google changed tacktic and does not pay attention to number of backlinks, how strong links are and PR too. Example? Please... Google.. keyword "Company formation uk" comparing two webs www.companieshouseonline.com and www.accounting-on-line.com. The first one in top 10, please, compare PRs and backlinks and you understand what I am talking about. Please, your comments
I think links play a large roll in all SERPS but MUCH more so in highly competitive keywords (try viagra etc). I also think that TrustRank is overlooked by many. Volume of links is a consideration but quality is hugely important. Getting the right link(s) to me is as important as anything else. Google doesn't talk about TrustRank much but they trademarked it and it plays a big role in SERP's and discounting link schemes and identifying bad neighborhoods.
www.companieshouseonline.com - Has 965 links, Has PR 1 www.accounting-on-line.com - Has 38 links, Has PR 4 For Google when a site gives a link to another site is casting a vote to that site. That is what we are seeing. If we compare other things like domain age -- companieshouseonline.com is registered in 2005 while the other one is registered in 2006. Also Meta Description of companieshouseonline.com isn't spammy but the other one has used about 100s of keywords in it. There could about 100s of more reasons.