Have you ever tried to add negative or excluded terms into Yahoo! Search Marketing and not found the appropriate functionality?? Well, look no further, after about 30 mins of scouring the deepest darkest crevices of one of my client’s campaigns I have found the way!
Unfortunately, unlike Google, it seems that you are unable to add negative terms (excluded terms) at account or campaign level. Instead, the option seems only to be present at Ad Group level.
When inserting a negative search term into Yahoo! you first must click on the campaign and then the ad group which you want the excluded term to be present in.
From here you then look to the top right hand side of the page and click on the Ad Group Settings drop down menu. From this, then click on Tactic Settings.
You will then see the following at the right hand side of the screen:

In order to view the excluded or negative search terms in the campaign you must click on the [show] option next to “Excluded Words”.
Once this has been clicked on, it will then open a text box where you can enter all of the negative or excluded terms which you want included in that specific ad group.
When you are finished adding in all of the appropriate terms, remember to click Save Changes, or you will have to repeat the process all over again!!