I believe an h1 tag should only be used once on a Web page. An h2 tag and/or h3 tag can be used for subheadings.
Google disagrees with you, and so do I. Read it for yourself: http://www.google.com/webmasters/docs/search-engine-optimization-starter-guide.pdf In addition, the website is the main topic. This is where the <h2 is important as the main topic of the page, as opposed to the <h1 being the main topic of the site.
Consider <h1> tag as you would structure an organization chart decreasing to <h2>, <h3> and even smaller depending on your site structure without forgetting the bolding within this tag to emphazise your site's main keyword.
http://www.google.com/webmasters/docs/search-engine-optimization-starter-guide.pdf has a lot of info actually.. I never knew that google had this kind of document!
While Google does mention the following in their starter guide: they are simply pointing out that you "could" use the <h1> element this way... because this is how lots of crappy templates on the web have used <h1> since way back when... like the late 90s. Even many current web designers who know nothing about SEO still perpetuate this terrible habit because they don't know any better. If you took a second to think about the example Google uses (instead of taking an example of a crappy web page created by someone who likely knows very little about SEO), then you'd realize that EVERY Page on a site built like this would have "Brandon's Baseball Cards" as the largest text at the top of the page... at the top of EVERY page on the site. That is terrible from a marketing and user perspective (not to mention from an SEO perspective). The user is likely on BrandonsBaseballCards.com and doesn't need you showing the site name in the H1 (biggest text) on EVERY page of the site to let me know where they are. That is so 1998 web design. If you read on you'll also notice that is the ONLY place where they mention the <h1> containing the site name. And they don't say that's what the <h1> is for... only that you "might" put the name of your site into an <h1>... if you want your site name to appear in the largest font at the top of each page. But anyone who knows anything about good web site design, SEO, and what header elements were create for in the HTML standard would know that is a terrible idea and not the intended use. Google even contridicts themselves. If you took the time to read on you'd see statements more in line with what <h1>...<h6> was REALLY designed for... to give the PAGE content structure... to outline the content of the PAGE (not the site). You'll see things like: Under Good Practices for Heading Tags they write: and they even go on to say: This document is Google's SEO for Dummies guide... It's written for an audience that knows absolutely nothing about SEO, and likely written by someone who knows very little about SEO.... Google is not going to publish anything that gives away significant details about how their ranking algorithm works. They are simply showing some common practices found on the web. The book Search Engine Optimization for Dummies provide 100 times more useful info than this PDF and that book still provides only rudamentary tips for SEO... the most basic concepts and terminology. How <h1> tags should be used should not be based on some starter guide to SEO when Google doesn't even like people using SEO to manipulate ranks... it should be based on the purpose of the tag in the HTML standard and how Google's algorithm uses the tag to rank your PAGE (again, they don't rank sites). If you REALLY believe that <h1> elements are supposed to be used to indicate what a site is about (even though the search engines rank URLs NOT sites), go for it... Waste the second most important on-page ranking factor that you could be using to help your page rank for its targeted keyword phrase. I base my decision to use it to indicate what the PAGE is about on the w3c's HTML standards for header elements (instead of blindly following some starter guide likely written by someone at Google who has never SEO'd a site in their life) since the w3c INVENTS the elements and set standards on how to use them. Did you bother to check out their description of what headers are for? Their example? I also base my decision to use <h1> to indicate the topic of the page on tests that have proven that the <h1> is second only to the <title> at most search engines as an on-page ranking factor in influencing how a PAGE ranks for a particular keyword phrase... Again, search engines don't rank SITES, they rank URLs or web PAGES. Don't believe everything you read or take it as the gospel JUST because it is found somewhere on Google's domain.
I'm convinced that only one <h1> are better. I got a good result by putting a keyword in title, one <h1> for that page keyword and one <h2> for site's keyword, then the rest of the page is just <p>. When all pages are connected together they'll all share the same theme of keyword due to title, <h1> and <h2> on each page. Doing this I can get a site ranks in low-competion keyword using only a few backlinks.
ofc. 1 H1 tag is sufficient but after putting several H1 tags, crawler confuses that whats the main topic of your page
The tags are set according to the priority and should be used wisely. Please keep in mind that the most important tag is the Title Tag and then the H1 Tag is important, keeping more than one H1 tag will harm you and lessen the importance of H1
Having header tags is always u useful one, but how many is the question? Header tag 1 is highly recommended for the page.