The answer to the most commonly asked questions are all here, plus there is a link to the original article written by Brian Dean with all 200 factors that can influence how Google ranks websites.
How important is the Domain Name and should you register a .com and a .com.au?
Keyword Appears in Top Level Domain: Doesn’t give the boost that it used to, but having your keyword in the domain still acts as a relevancy signal. After all, they still bold keywords that appear in a domain name.
Country TLD extension: Having a Country Code Top Level Domain (.cn, .pt, .ca) helps the site rank for that particular country…but limits the site’s ability to rank globally.
Geo Targeting: Google gives preference to sites with a local server IP and country-specific domain name extension.
Domain Age: The age of a site is a significant factor. 6 months or a year? Maybe not. But if a site is 2 or more years old, it will rank higher than another site with more content and more recently updated content. I’ve seen it often.
The importance of Page Titles for every page.
Keyword in Title Tag: The title tag is a webpage’s second most important piece of content (besides the content of the page) and therefore sends a strong on-page SEO signal.
Are keywords still important?
Keyword Density: Although not as important as it once was, keyword density is still something Google uses to determine the topic of a webpage. But going overboard can hurt you.
Site Over-Optimization: Includes on-page factors like keyword stuffing, header tag stuffing, excessive keyword decoration.
Can Page Load Speed affect your site and is proper image optimisation necessary?
Duplicate Content - does Google score this poorly?
Duplicate Content: Identical content on the same site (even slightly modified) can negatively influence a site’s search engine visibility.
Does how much and how often Content is updated help?
Recency of Content Updates: Google Caffeine update favors recently updated content, especially for time-sensitive searches. Highlighting this factor’s importance, Google shows the date of a page’s last update for certain pages:
Do images and video help the quality content score?
Multimedia: Images, videos and other multimedia elements may act as a content quality signal.
Using bullet points and numbers actually helps when used in content.
Bullets and Numbered Lists: Bullets and numbered lists help break up your content for readers, making them more user friendly. Google likely agrees and may prefer content with bullets and numbers.
If you have 10 domain names pointing to your website, will you rank better?
Parked Domains: A Google update in December of 2011 decreased search visibility of parked domains.
Why a business should register their own domain names. It is important for the whois data in the registry to match the contact us details on the site.
Contact Us Page: The aforementioned Google Quality Document states that they prefer sites with an “appropriate amount of contact information”. Supposed bonus if your contact information matches your whois info.
Did you know that there is Freshness Factor?
Site Updates: How often a site is updated — and especially when new content is added to the site — is a site-wide freshness factor.
Query Deserves Freshness: Google gives newer pages a boost for certain searches.
Responsive or mobile website - what's the very latest news?
Mobile Optimized: Google’s official stance on mobile is to create a responsive site. It’s likely that responsive sites get an edge in searches from a mobile device.
Does having video content on You Tube help?
YouTube: There’s no doubt that YouTube videos are given preferential treatment in the SERPs (probably because Google owns it :-) In fact, Search Engine Land found that YouTube.com traffic increased significantly after Google Panda.
Can linking from other hotel websites help?
Links From Competitors: Links from other pages ranking in the same SERP may be more valuable for a page’s rank for that particular keyword.
How important is the social share tool?
Social Shares of Referring Page: The amount of page-level social shares may influence the link’s value.
Are links in a page important?
Contextual Links: Links embedded inside a page’s content are considered more powerful than links on an empty page or found elsewhere on the page. A good example of contextual links are backlinks from guestographics.
How important is having lots of traffic to your site?
Direct Traffic: It’s confirmed that Google uses data from Google Chrome to determine whether or not people visit a site (and how often). Sites with lots of direct traffic are likely higher quality than sites that get very little direct traffic.
Did you know that Google use your browser and search history as a factor?
User Browsing History: Sites that you frequently visit while signed into Google get a SERP bump for your searches.
User Search History: Search chain influence search results for later searches. For example, if you search for “reviews” then search for “toasters”, Google is more likely to show toaster review sites higher in the SERPs.
Can Google+ give you a boost?
Google+ Circles: Google shows higher results for authors and sites that you’ve added to your Google Plus Circles.
Brick and Mortar Location With Google+ Local Listing: Real businesses have offices. It’s possible that Google fishes for location-data to determine whether or not a site is a big brand.
Is Pinterest any help?
Pinterest Pins: Pinterest is an insanely popular social media account with lots of public data. It’s probably that Google considers Pinterest Pins a social signal.
Read the full article by Brian Dean