To say "SEO has changed a lot” would be the understatement of the decade. Just take a look at how Google’s Panda and Penguin algorithm updates shook the world of SEO professionals. Marketers and SEO agencies worldwide halted their link-building and keyword-obsessed ways, and swapped it for a long overdue focus on quality content.
But does that mean an SEO’s job is just to pump out high-quality, keyword-optimized content? Far from it. In fact, SEO has changed so much in the past several years that many marketers aren’t sure what’s outdated, what’s important, what will actually move the needle, and what’s simply a wasted effort. This blog post, an excerpt from our new ebook, 17 SEO Myths You Should Leave Behind in 2013, will point out seven of the most common myths and assumptions about how SEO works, and debunk them for you so you’re not wasting a single moment on things that simply don’t matter for SEO moving forward. Ready to throw some of your false SEO beliefs out the window? Let’s get started.

Myth #1: We Must Rank Number One

Studies of clickthrough rates and user behavior have shown that searchers favor the top search results -- particularly the top three listings. However, it’s also been shown that on subsequent pages, being listed toward the top of the page shows similar click behavior.
Now with search results also being appended with author profiles and rich snippets, clickthrough rates are proving to be higher on those listings even if they don't appear among the top results. The takeaway here is that relevant information and user-friendly listings are more valuable than just rank alone. So, no, you don't need to rank in first place anymore to see success.

Myth #2: Keywords Need to Be an Exact Match

Keywords do not need to be repeated verbatim throughout a piece of content. In titles in particular, it's far more important to use keywords in the way it makes most sense. Write a stellar headline (somewhere around 4-9 words) that focuses on clearly explaining what that particular piece of content is about. Nothing is more of a buzz kill than reading a headline
that’s awkwardly framed around one keyword phrase or, worse, one that forcibly repeats a keyword phrase. Keep in mind that this rule applies to both headlines and content on the page, too.
And in terms of the "ideal keyword density" for a given page, there is also no magic number. This myth is like a pesky little fly that keeps coming back no matter how many times you swat it. So for everyone who still clings to this one, there is no ideal number of times you should repeat a keyword on a given page. You should, however, make sure your keyword(s) are included in your page title. After all, how else will people know what your page is about? The keyword (or a variation of it) should also be included in a headline on the page, ideally also within the URL, and at least once within the content. Again, the goal is to make your content clear and to meet the expectations of the searcher; that’s why they clicked through to your page, so don’t assault them with over-optimized content.

Myth #3: Social Media & SEO Aren't Related at All

The intersection of SEO and social media is referred to as “social search.” And yes, social search is very much a real thing. An increasingly formal relationship between search and social has been evolving for years, and Google has been working hard to prove this with Google+ and Google Authorship. It’s a natural extension of what has always been true: Content that’s relevant and can be trusted as authoritative will continue to drive both your search and social media marketing.
In social search, content that has a social connection to you in some way is prioritized, which could mean someone you are linked to via Facebook, Twitter, or any other major social network. Alternately, some forms of social search prioritize content that has been shared by social media influencers, even if those experts aren’t directly tied to you. The lesson, folks, is to make sure you have a social media strategy and think of it as part of your search engine optimization efforts -- the two should not be working as silos. If you're looking to learn more about social search, this blog post has a crystal clear explanation of how social media influences SEO.

Myth #4: The H1 Is the Most Important On-Page Element

Think of the content structure on your web page as an outline. It’s a tiered approach to presenting information to a user -- and to search engines. What title tag that headline/thesis is wrapped in has little to no influence on your overall SEO. In fact, that title tag (whether H1, H2, H3 …) is only used for styling purposes. The H1 (heading 1) tag is simply part of your CSS (cascading style sheet), which a designer puts together to reference what font styling and size will be applied to a particular piece of content.
This used to be something that was more important. Now, however, search engines are much smarter than that, and unfortunately, people spammed this to death. So it really doesn't matter what header tag you use as long as you present your most important concepts up front, or closer to the top of the page. Remember, you are optimizing your page for users first and foremost, which means you should want to tell them ASAP what your page is about through a clear headline.

Myth #5: Microsites and Other Domains I Own That Link or Redirect Back to My Site Will Help My SEO

The chances of this doing much for you are slim to none. It’s like voting for yourself a thousand times in an election: It will still only count as one vote. Search engines are smart enough to know who a particular domain's registrant is, and they'll see that it’s the same person as your primary domain. And if you're reading this and thinking, "But what If i just change my registration information?" then you are clearly thinking like a spammer. Don’t be that person.
Furthermore, there isn't much value in spreading your SEO thin, which is what you'll end up doing by setting up domain after domain ... after domain ... and optimizing each separately rather than putting all that love into your primary domain. Why not just add that content to your primary domain, or build a tool as an add-on to your website?

Myth #6: More Links Is Better Than More Content

This myth is one that often comes along with the question, “Which should I invest in -- link building or content creation?” Yes, inbound links are an important part of your website’s authority (even with the changing link landscape); however, if you have budget to invest in your website, I would say, “Hire someone to write for you” in a heartbeat. All too often, when businesses hire someone to do link building, they focus on the quantity rather than the quality of those links. But linking is not a numbers game anymore. Instead, it's more important to focus on attracting relevant and diverse sources that link to relevant pages on your website. And when you invest in content, which can take the form of web pages, blog articles, lead generation offers, and guest articles on other sites -- these are all content assets that will enable you to generate more inbound links over time.
That being said, if you're among the group of people who think that as long as you have a good blog or some good content, then your SEO is secure -- I wouldn’t go that far. Don’t get me wrong, good content will take you a long way, but it can’t be the only tool in your SEO tool kit. Years ago, when HubSpot first started teaching people about search engine optimization, one rule was essential: Above all else, create high-quality, useful content. But now you need to ask yourself more of the following: Are you writing with a purpose? Who is your target audience? Have you analyzed your traffic sources and top performing posts? What keywords are you targeting? If all of these sound foreign to you, then you’re missing the mark,
and content alone will only get you so far.

Myth #7: SEO Is Not a Usability Issue

This one truly grinds my gears. SEO has evolved from simply getting found, to improving how users engage with your content. In fact, SEO, which technically stands for search engine optimization, is so much more than just optimizing for search engines. First and foremost, you need to optimize for users so they actually click through your search listings to your website. And once they click through, they should stay there.
To keep visitors on your site, ensure that you’re publishing content that’s both personalized and relevant to your target audience. You should also make an effort to create a website that's intuitive and easy to browse through (accessible by search crawlers and users). Don’t make visitors look for what they need. Display clear calls-to-action, and you’ll be much more capable of converting those users. That’s what SEO is really all about -- search experience optimization.
Curious to know what other common myths might be negatively influencing your SEO strategy? Download our ebook for the full list of commonly believed SEO myths so you can base your SEO strategy on fact -- not fiction.

Source : http://blog.hubspot.com/blog/tabid/6307/bid/33926/7-Common-SEO-Myths-to-Throw-Out-the-Window-Immediately.aspx