Search Engine Optimization (SEO) affects only organic search results, not paid or "sponsored" results such as Google AdWords.
When a search engine returns its search results, it gives you two types: organic and paid. Organic search results are the Web page listings that most closely match the user’s search query based on relevance. Also called “natural” search results, ranking high in the organic results is what SEO is all about.
Paid results are basically advertisements — the Web site owners have paid to have their Web pages display for certain keywords, so these listings show up when someone runs a search query containing those keywords.
On a search results page, you can tell paid results from organic ones because search engines set apart the paid listings, putting them above or to the right of the organic results, or giving them a shaded background, border lines, or other visual clues.
SEO & Links - How to Have A Google Friendly Site
Provide high-quality content on your pages, especially your homepage. This is the single most important thing to do. If your pages contain useful information, their content will attract many visitors and entice webmasters to link to your site. In creating a helpful, information-rich site, write pages that clearly and accurately describe your topic. Think about the words users would type to find your pages and include those words on your site.
Make sure that other sites link to yours
Links help our crawlers find your site and can give your site greater visibility in our search results. When returning results for a search, Google uses sophisticated text-matching techniques to display pages that are both important and relevant to each search. Google interprets a link from page A to page B as a vote by page A for page B. Votes cast by pages that are themselves "important" weigh more heavily and help to make other pages "important."
Keep in mind that our algorithms can distinguish natural links from unnatural links.
Natural links to your site develop as part of the dynamic nature of the web when other sites find your content valuable and think it would be helpful for their visitors.
Unnatural links to your site are placed there specifically to make your site look more popular to search engines. Some of these types of links (such as link schemes and doorway pages) are covered in our Webmaster Guidelines.
Only natural links are useful for the indexing and ranking of your site.
SEO: Will Google rank web pages based on how accurate they are?
As New Scientist recently reported, a team of research scientists at Google has published a paper (PDF) explaining the idea of Knowledge-Based Trust (KBT), an alternate way of determining the quality of web pages by looking at how accurate they are.
"The quality of web sources has been traditionally evaluated using exogenous signals such as the hyperlink structure of the graph. We propose a new approach that relies on endogenous signals, namely, the correctness of factual information provided by the source. A source that has few false facts is considered to be trustworthy."
The paper goes on to describe how Google could use an extraction process to compare the facts it finds on web pages to facts that are stored in a knowledge base (think Knowledge Graph/Knowledge Vault), and reward pages that are found to be more accurate. In cases where a single web page doesn’t have enough facts, the paper suggests relying on other pages from the same website to determine trustworthiness.
Google has been building a massive database of known facts for years, and in 2012 introduced its Knowledge Graph. That’s the source of those information boxes that show on the right side of Google search results (primarily) for searches involving people, places and known entities.
Organic Search Results - 10 Questions To Guide Your SEO Results
If you're thinking about hiring an SEO, the earlier the better. A great time to hire is when you're considering a site redesign, or planning to launch a new site. That way, you and your SEO can ensure that your site is designed to be search engine-friendly from the bottom up. However, a good SEO can also help improve an existing site.
#1 Can you show me examples of your previous work and share some success stories?
#2 Do you follow the Google Webmaster Guidelines?
#3 Do you offer any online marketing services or advice to complement your organic search business?
#4 What kind of results do you expect to see, and in what timeframe? How do you measure your success?
#5 What's your experience in my industry?
#6 What's your experience in my country/city?
#7 What's your experience developing international sites?
#8 What are your most important SEO techniques?
#9 How long have you been in business?
#10 How can I expect to communicate with you? Will you share with me all the changes you make to my site, and provide detailed information about your recommendations and the reasoning behind them?
The above content is provided by Google. We display it here because we believe these are the 10 best questions to ask BEFORE you hire someone to do your SEO work.