One of the most frequently requested features we've had is a way to give some ads more weight than others in terms of how often they appear in random ad groups or in rotating ads. The Weighted Ads Add-On for AdSanity provides that functionality.
Easy to Set
Now when you're creating an ad you can give that ad a weight that indicates how often that you'd like that ad to appear whenever you're using a random display of ads.
Remember that these settings are relational so you'll want to be aware of the settings that you're making for all of the ads in the same group. If everything is set to "highest" then the ads will display with about the same frequency.
Requirements: All Add-Ons require the latest version of AdSanity Core.