The belief here is that the keywords you use in H2-H6 subheadings are more heavily weighted in Google’s algorithm than words in plain text and that tags are therefore a ranking factor of their own.

Are there any implications to SEO for webpages that skip H2s and go directly from an H1 to an H3? Find out in this edition of Ask an SEO. One question I can’t seem to find substantial answers to is: ...

There is an old WebmasterWorld thread on the topic of how many header tags (i.e. H1, H2) you should have on a page and how you should use it. The thread was revived yesterday when Matt Cutts of Google ...