For example, do a search for the term “sports” and you'll find that ESPN holds the top spot in Google, while Yahoo! Sports holds the top spot in Yahoo and Fox Sports holds the top spot in MSN.

Of course, then again, if you do a search for “hotels”, you'll find that http://hotels.com has the top spot in all three search engines.

So what's a person to do when optimizing their websites?

My advice is to focus your attention on optimizing your website to rank well in Google. Yahoo and MSN combined don't send as much traffic as Google will if you hold the top spot. Since Google gets nearly half (about 49%) of ALL search engine traffic, it's makes sense that you'd want to focus your efforts on Google.

Also, since Google has the reputation for providing the most relevant results, Yahoo and MSN tend to always be playing catch up. So what's working well in Google will likely work for both Yahoo and MSN.

However, if you optimize for just Yahoo or MSN, you're not likely to rank as well in Google.

One thing I also like about Google is how fast they're currently updating their index. You can get a website up, get a few links, and be indexed in less than a week. Yahoo and MSN tend to be a lot slower in getting your website indexed. Also, the rankings change less often in Yahoo and MSN, which is great if you hold the top ranking, but not so great when you're trying to climb up in the rankings. With Google's frequently updating index, you get more feedback on how well your search engine optimization efforts are paying off.