For those of us who can't place the conversion tracking code on merchant's landing page, setting up conversion tracking with YSM URL tracking is easy. You can grab the search keywords from the tracking URL (using little PHP code), that yahoo appends to your URL when someone click on your ad and use that in your sub to see the conversions. Does google append search keywords to the URL when someone comes though google search? I couldn't find this info anywhere.
just use {keyword ..http://azgredirect.com?sub={keyword} .. there is also a php script to track conversions with MySQL on this blog: http://oooff.com/php-affiliate-seo-blog/