Search Engine Optimisation is the process of developing a website’s coding, content and link relationships so that it achieves high search engine rankings for targeted search terms.

How Search Engines Index Websites :
Search engines use automated software programs called spiders, also known as robots, to collect information about individual web pages, which is then stored in the search engine’s index. An important part of the initial search engine optimisation process is ensuring that a website is spider friendly. A spider friendly web site is one that a search engine spider can navigate around easily in order to access the information on the individual pages. Website technologies and techniques which can prevent spiders indexing a web site include the use of framesets, JavaScript navigation, Flash, explicit session IDs, dynamic content and a requirement for users to log in to the website.

Search Engine Results:
Search engines use algorithms (complex mathematical formulae) to determine the order in which websites rank in the search engine results pages (SERPs). When a search is performed, the websites which rank highest in the search engine results are those which are calculated by the algorithm as being most relevant to that particular search term.

Search Engine Ranking Factors :
Google has stated that its algorithm uses over 100 different factors to determine a website’s relevance and importance. These ranking factors can be broken down into three main groups:

1. Content - The presence, position and repetition of keywords and key phrases on the page are all taken into account by the algorithm
   
2. Coding - Analysis of the (X)HTML code provides additional weighting factors for text, images and other individual page elements
   
3. Links - The quantity, quality and link text of inbound links (IBLs) and internal links are amongst the most important ranking factors

Reverse Engineering Search Engine Algorithms:
The key to successful search engine optimisation is the ability to reverse engineer search engine algorithms to determine which elements are important ranking factors for each individual search engine. The search engine optimisation process then involves redeveloping the website’s coding, content and links to include or enhance the key ranking factors, ensuring that individual pages achieve high rankings for selected keywords or key phrases.

Search Engine Plurality:
Since each search engine uses a different algorithm, incorporating constantly evolving ranking factors, it requires expert search engine optimisation to ensure that high search engine rankings are achieved and maintained across a range of targeted search engines. Optillion’s search engine optimisation campaigns usually target the three major search engines – Google, Yahoo and MSN – which between them carry over 90% of UK search traffic, although other search engines can be targeted if required.