Google might have the lion’s share of the search market, but Bing and Yahoo! are still important. Between them, they have close to 15% of the search market. Of course, they fluctuate up and down and at times have a total of 20% between them. Usually, Bing has a little more than Yahoo! and that’s okay. Not everyone can be on top.
While all the search engines generally look at some of the same criteria, there are differences.
Bing is more closely aligned with Facebook. You can push your Bing rankings higher if you have a strong Facebook network and promote your links to your Facebook friends. Google has its own social network with Google+. Yahoo!, however, seems to be more interested in domain names with age. Google likes aged domains as well, but with over 200 ranking algorithms any one ranking factor is going to have less influence on its own.
The differences between the search engines tell me that diversity is very important. You don’t want to rely on just one search engine for all of your traffic. You want to diversify your traffic sources.
This is very important. If some new website next year starts taking traffic away from Google and the search giant fades into oblivion (remember MySpace?), then you will be thankful you diversified your traffic sources. That’s why Bing and Yahoo! are still important.