As of this moment I have 6 domains I am running (AdSense and Affiliate income). Of the 6, one is ranking on page 5 or 6 just by having the keyword in the domain (not EMD tho), having good on-site SEO and having 1,500 words of content on the homepage. It is a thin site with only 2 posts, but it is also a 50,000 search/month keyword. I have not built a single link for this site, and have done nothing but one socialadr blast (which did some good in the short term but nothing lasting). I did not even go through the Google Dance with this site; page 5 or 6 just by having lots of content.
My second site I started before I knew how to do keyword research properly. After starting the site I learned how to do research, and let's just say I wouldn't have gone for this KW had I known how to do it right in the first place. With that said, by having 800+ words on the homepage and using great on-site SEO, my site is on page 1 despite being a mere three months old. As for link buildling, I am doing 1 or 2 BMR posts maybe 5 days/week since Feb. 1st, and did not start varying my anchor text until maybe 2 weeks ago. I have no doubt I can move up into the top three once I start doing link-wheels/pyramids and moving beyond BMR links.
On the other hand, 3 of the other 4 domains I am running that only have 500 words of content on the homepage (and no more than 800 in some of the posts) are not doing so well despite the fact that I am using the same exact link building strategy (BMR and occasional SocialAdr blasts). Further, the keywords I'm pursuing on these sites are less competitive (sometimes much less) than the second site I already have on page one. The only one that is doing well is in an odd niche, and I am convinced it's doing better because I waited a month before sending BMR links (versus sending them in the first 2 weeks, which is another case study I'll be posting eventually).
Because of this I am now updating all of my homepages to 1,500 words minimum. Somebody else posted on here a while ago how he had been building links for weeks and nothing was working, but when he sat down and cranked out a 5,000 word post he jumped up to page one virtually overnight. The post gained some attention but not too much, so I thought I would reinforce what he learned here.