There are many misconceptions about search engine optimization. It seems that anyone that has ever worked with a website has theories on how to rank well in search engines like Google. Remember just because someone claims to be an expert in SEO (Search Engine Optimization) does not mean they really are. There are far more misconceptions and unproven theories about SEO than you might think.
You should really consider the source when taking advice from so called SEO experts, be skeptical, and always research before spending time and/or money making changes on your website for SEO value.
An engineer from Google, Matt Cutts, answers some questions about Google search engine SEO basics and some misconceptions in this video. You should also check some of the other videos I posted of Matt Cutts.