As all we know Yahoo search marketing has improved a lot on advertising in both search and content network. Apart from Yahoo search advertisers ads are also displayed in Yahoo search partners. AAs a advertisers we have to be very much care in optimization in YSM. In some cases Y search partners websites may give good conversions while compare to the Y Search but its not applicable in all cases. It depend up on the products. So the advertiser has to keep an eye on Y! search partners, some website may simply cost with out any conversions. There is a new report option available in Y! search marketing interface to help optimizing campaign ie: ” Ad Delivery Report” under “Traffic Quality Reports” section. Which gives the cumulative search partners performance report. By excluding the non performing search partners you can stand away from costing high without any conversions
Follow the instruction to get “Ad Delivery report”

Go to Reports tab. You can find Ad Delivery report at the bottom. Click on Ad Delivery report and select at least 3 to 5 month date range. At the top of the report, change the 'Distribution' to Yahoo Partners. Then select a date range and sort the data by cost. You'll easily be able to see if certain search partners are costing a ton and without any conversions.
Once you find search partners that are not performing well for you, you can actually add them as blocked domains under the 'Administration' tab:. You can block both domain and sub-domains. Totally you can block up to 500 domains.
Adding search partner domains and sub domains are currently only an option in Yahoo, as Google will allow you to either opt in or out of their search partner network. In Google we can do the exclusion in both campaign level and adgroup level for content network where as in Y! Search marketing it can be done with account level. So you have to make clear analysis before you go and exclude the domains. Let’s hope Google will come up with the search partner exclusion soon.