Depending on your site statistics program, you may also be able to see which search engines are referring traffic to your site. Google Analytics will provide graphical charts to represent site traffic.
Don’t expect to get every page ranked in every engine. Some search engines just naturally pick up more pages than others. Search engines are always in a competition for who has the biggest database of web pages. You may find that one search engine may be picking up and ranking almost every page of your site, while another engine only likes your home page. It is also dependent on the popularity of the specific search engine.
We’ve dealt with the statistics for many web sites over many years. We believe that Google sends the most traffic. But that doesn’t mean that Google always sends the most quality traffic. Quality traffic (traffic that produces sales) can vary by search engine. One important variable would be the product. For instance, traffic from MSN may bring many sales for your product, whereas traffic from Google may yield you less sales per unique visitor.
You will need to look at your statistics over many months to determine which engines are bringing you sales and which keywords are producing traffic and sales for your specific product.