In Part 1 and Part 2 of How to Optimize for Google I discussed general website optimization, links, and Google webmaster tools. In Part 3 we will look at a number of other considerations which play a role in successful rankings in Google, and also touch on some tactics which are best avoided.

Completing Optimization: Other Considerations

Redirects
If you need to use redirects on your site, it is very important to use the correct one. If a page is moving to a new location, or being removed all together, it is very important to have this page redirected to either the new location or the next closest page using a Permanent 301 Redirect.

While rare, if a page is being moved to a new location for a short term, with the intent of it returning to the original location, then and only then, will you want to use a Temporary 302 redirect. For more information please see Redirects: Permanent 301 vs. Temporary 302 .

Non WWW Redirects
To help eliminate page rank split, and provide your site with a little extra value, implement a non-www redirect. What this redirect will do is change the URL to include the "www" whenever a URL is accessed that does not include it. This can help to consolidate links to the correct page and give your site some additional strength. For more help on Non WWW redirects please see: How to 301 Redirect Non-WWW to WWW URL's

HTTP Headers
Check your page headers! If you have implemented any form of redirect on your site including mod rewrites, check your HTTP headers. You may be surprised at what you find. Some forms of redirects may use a 302 code where you really want a 301. By checking your headers you can ensure all is well, and troubleshoot problems. On our website we have added our own HTTP Header Checker for your convenience.

Home Page URL
Never have more than one URL for your home page. If your home page is available and displays on more than one URL, then utilize 301 redirects on all but the main URL you want to focus on - in most cases "http://www.domain.com/". All your links pointing to the home page should direct to the exact same URL otherwise you will split the value of your home page into multiple duplicate URL's.

Google sees "http://www.domain.com" and "http://www.domain.com/index.html" as different pages, but displaying the same content. This splits the overall value of your home page, and can decrease the chances of rankings. By keeping it consistent with a single URL, you remove this split and retain more of the strength.

In theory having your home page split like this could bring with it duplicate content penalties, however, I have yet to see this actually happen - that said, it is best to avoid the risk all together.

XML Sitemap
XML Sitemaps are great for ensuring that Google and the other engines are able to spider your entire site. While an XML sitemap will not directly impact your search rankings it can help as Google is more likely to see any SEO based changes more quickly, which in turn can have an impact.

Robots.txt
This is the first file all search engines look for every time they visit your site. While placing a blank robots.txt file in your root folder will not help with search rankings, it will help reduce 404 errors appearing in your log files.

It is also highly recommended that if your site utilizes an XML sitemap, to include a call to this sitemap within the Robots.txt file. Simply add the

following line to ensure that the major engines (including Google) can find your sitemap:

      Sitemap: http://www.domain.com/sitemap.xml

Potential Blockages
If you are finding that your site is simply not being indexed it is possible that you are blocking the spiders in one way or another.

Start with checking your main site navigation, if you are using Flash or some other fancy form of navigation that could be your problem right there. Next check your HTTP headers to ensure that your home page is returning a 2xx code which indicates that the clients' request was successfully received. Finally take a look at your Google Webmaster Tools for any noted errors. If you are blocking Google, chances are you will be able to uncover the issue with these steps.

Duplicate Content
Duplicate content can be quite damaging to your rankings. Ensure that all content on your site is unique. Never steal or "borrow" content from another site, and never cut and paste large portions of text from one page of your site to the next. By keeping all pages of your site entirely original you stand the best chances of getting a thumbs up from Google.

Fresh Content / Regular Updates
Update your content. In highly competitive markets, sites with old static content can often slip away. Keep your content fresh and updated to keep bringing Google back to your site. If they find new pages and updated pages with every visit, they will come back more often.

Site Age
The age of your site can also have an effect on search engine rankings. While there is little you can do (short of keeping the same domain) to help on this matter, remember that the longer your site is online, the better its chances for success. It pays to select the perfect domain right from the start and not to change domains mid-stream. Older sites that stand the test of time add a level of authority in Google's eyes. New sites seldom see rankings for competitive terms in their first year.

Note: Site Age is determined not by the date the domain was originally registered by rather by the date Google first discovered content on your site.

Load Time
Load time can have an impact in your Google AdWords Quality Score but it is unknown for sure if it can also impact your organic search rankings. It is best to keep your load time to as little as possible. If it is not already a part of the Google Algorithm, it likely will be soon. Besides, it is also best in order to give your site visitors the best experience possible.

Server Up Time
This can be a rather significant issue. If you find that your web hosting company has a history of down time, change hosts. If Google comes to visit your site once and it is down, not to worry, they will come back, but if Google visits your site often only to find that it is unavailable, you can find yourself with drastically depleted rankings.

Google Local
If you have a traditional brick and mortar store, consider submitting to Google Local . While this will not directly impact your regular organic rankings, you may find your site ranking above the organic results with a "local business results" map listing. This tends to be most common when your business is near the geographic center of a city, and when the search phrase uses a geographic modifier.

W3C Compliant Code
There is much speculation as to if W3C compliant code can have a positive impact on search rankings, and the majority believe "maybe" with some saying "yes". Regardless, it is definitely a good idea to have your site be W3C Compliant if at all possible. Not only may it help you in terms of search rankings, but having compliant code can decrease load times, and help to ensure cross-browser compatibility, all of which are good things. If at all possible, it is recommended that sites be made to be compliant.

Many experts who took part in the SEOMoz "Google Search Engine Ranking Factors" lean towards it not being a big contributor, however, it may be an issue if Google has difficulties indexing a page properly.

A code validation service is available at validator.w3.org .