Google is the most popular search engine and as such is the hardest to optimize for. Google pays attention to inbound links more than anything. Of course on-page optimization is also a factor but a small one.

The importance google gives to inbound links can be observed in keyword rankings. The more relevant inbound links a page has the higher up in the results it appears. I emphasize the word “relevant” as any old link will not make much of a difference.

A second factor of google rankings is domain age. The domain age is calculated not by the date the site went live but from the date the google spiders found the domain. The older a domain is the more trusted it is and therefore appears higher in the results. Google has implemented this technique to get rid of SPAM pages that litter the web.

MSN is a fairly large search engine with a far reach and only comes second to Yahoo and Google. However, optimisation of MSN is not that difficult compared to the other two.

MSN focuses more on keyword density and quantity of links rather than the quality of links.

This is emphasized by the number of websites getting number 1 spots with a small amount of inbound links.

MSN is also one of the fastest search engines to include a website in their index and rank the pages. This is why most webmasters see traffic only from MSN in the early days of a website, then gradually start seeing traffic from Google and Yahoo in the following months.