For which Search Engine should a site be optimized?
Statistics on the popularity of various Search Engines can be obtained by loading the site log and comparing the quantity of hits from each Search Engine on requests for which your site is a leader on all these Search Engines. You can use the name of your product as an example of such a request, but I hope you have more leading requests than just this one.
The indisputable leader among Search Engines is Google. According to my data, Google accounts for 81 % of all requests. Next are Yahoo-7%, MSN-5%, Yandex-1%, Altavista-1%, AOL-1% and Search-1%. The Yahoo search directory uses Google for searches, therefore actually almost 90 % of all requests are fulfilled through Google.
On the technical side of optimization, it's best to orient yourself first of all on Google and its mechanisms for ranking search results. But don't imagine that technical optimization alone will solve the problem of attracting traffic. It's visitors who decide whether your site will have traffic. Technical optimization is only a mechanism for initially attracting traffic, but then content, design and presentation of material becomes important.
Optimization should be done not for Search Engines but for the visitors to your site. Google determines the quality of content using a feedback mechanism. In effect, visitors vote on the quality of a site. And that's why optimizing a site for the visitors gives you a better chance of coming out on top in search results.