I found that my yahoo search traffic is down 50%, I also found that they last processed my sitemaps on October 2006, Please help so that I can increase search traffic. I was looking at Yahoo Site Explorer.. Also please suggest, if is there could exist some problem with my sitemaps , due to which Site's traffic is low? Is there need for some modification in the sitemaps or what are the ideal conditions to be added in the sitemaps...
Most likely you just dropped in rankings. Check your rankings and see where you lost ground. I assume your competitors just did enough work to pass you. So you probably need to keep adding more content and more links.
How do you analyse your traffic? Check the keywords you get traffic from, I would assume you have dropped, that's it. Or you've got some sort of season-dependent site and nobody looks for your service at this very moment!
Check whether your server is 100% available or not. Just check the SERPS in Yahoo. Even one place change will affect the traffic. So know the possible reasons...