SEO Friendly can mean many things. It’s not always a gimmick or buzzword IMO . Here’s an oversimplified example, Semantic HTML can make it easier for search engines to crawl, index and rank your site. More importantly, it may make it more clear to the bot what the really important parts of your site are. It prioritizes site elements and you can capitalize on those if you’re aware of them.
Details here – http://en.wikipedia.org/wiki/Semantic_HTML
With so many ways to torch your SEO performance, “SEO Friendly” may indicate that the theme author actually had some SEO best practices in mind (to whatever degree) when authoring the theme. Examples of things that can affect your SEO negatively are using Adobe Flash to display your content. Converting all your text to graphics because it’s easier than other methods for typography display, you don’t know better, etc.
Ultimately though, even with the most thoughtful author in terms of SEO without well executed content it doesn’t matter. An “SEO Friendly” theme can often present your content to search engines better than one that isn’t. However, this assumes at least a basic familiarity various SEO plugins / practices affect your site. A “SEO Friendly” theme + top quality content + good execution is a good start.
When we are talking about SEO , this periodic table is worth to check http://searchengineland.com/seotable
You can see that there are many factors of SEO , but we can split them to On Page SEO and Off Page SEO .
We can’t provide all SEO factors from a Wordpress Theme, it will not be enough.
Our job (theme developer) is creating a good start for our theme user to get better SEO . That is what we call SEO Friendly Wordpress Theme.
What You Can Do To Create SEO Friendly Wordpress Theme
[ONPAGE SEO – Ac] Main Content should be indexed first before the sidebars, and don’t add too many content to your header.
It is really important when you create “sidebar – content” layout or “sidebar – content – sidebar” layout. Your content should be called first before your sidebars in the HTML code.
[ONPAGE SEO – As] Speed Optimization
Your theme should be fast enough. And your theme should support any Cache / Minify plugin to make it faster.
[ONPAGE SEO – Au] Good Permalink Structure
Encourage your theme users to use the best Custom Permalink Structure for better SEO . Don’t forget to put this information in your theme documentation
[ONPAGE SEO – Ht] Good HTML title tags.
You can add simple Wordpress filter to make your HTML title tags SEO Friendly. It is useful for newbie, when they know nothing about SEO .
You can also add additional settings to control HTML title tags. But, you can also direct your theme users to use Yoast WP SEO , All In One SEO , and others for advanced HTML title tags control
[ONPAGE SEO – Ht] Meta Description Tag Control.
It is useful to control the appearance of your search engine result. You can also add additional settings to control meta description tags. But, you can also direct your theme users to use Yoast WP SEO , All In One SEO , and others for advanced meta description tags control
[ONPAGE SEO – Hh] Proper h1/h2 placement.
When in homepage / archive page, you should use H1 for your website title, and H2 for others.
When in single post/page, you should use H1 for your single post/page title, and H2 for others.
[ONPAGE SEO ] Inner Linking
Adding related posts / related products feature is also important for inner linking.
[OFFPAGE SEO – Ss] Social Media
Social networks has good SEO impact when we use it properly. Your theme should have Share This (FB/Twitter/G+) feature.
So, that’s our job as a WP Theme Developer. The rest is our theme users job, how they create high quality content, how they create a good online reputation, how they create a good online authority, and how they manage their backlinks.
......... Good SEO comes from knowledge and a good plugin (Headspace2), not a theme
If I may… I do not agree. NOTHING is more important then content. Good, unique and regularly updated content. Nowadays Google is not an algorithm anymore… it is an intelligence that can read and interpret what you are saying and doing… Backlinks are worthless if you got 100.000 of them in 2 days… but if you got them in 2 years then that’s gold.
... and there are so much more....just my 2 cents.
Sorry, I thought “content is king” went without needing said
But don’t let anyone fool you that spam doesn’t still work on Google either. Got plenty of my competitors examples to prove it
Agusmu’s nailed it, thread over.