If you’re already a believer in on-page SEO, it probably won’t come as a surprise that Matt Cutts made the admission that placing keywords early on your page makes a difference. However, there are plenty of SEO professionals out there who claim that factors such as these are unimportant, and provide anecdotal ‘evidence’ by claiming they’ve done fine without using it (or giving it much attention).
For this reason, it’s important to note that the famed Google engineer himself made this admission at the WordCamp 2007 conference in San Francisco, CA. The entire video is worth watching, as he gives several helpful tips for bloggers (1:02:20 into the video is where he makes the aforementioned admission).
Matt Cutts: SEO Tips for Bloggers