(metric) The prior attribution rate indicates the ratio of organic visits which follow from visits generated by campaigns. Amongst these organic visits, we can consider that a large part of them come from direct access, in other words from bookmarks.

This metric also lets marketers evaluate how good (or bad) a campaign is at obtaining Internet user interest. Comparing the prior attribution rate of several different advertising campaigns allows marketers to decide which campaign should be used based on its capacity to capt Internet user interest. 

Similar definitions : 

Attribution rate: Shows the share of attribution and is calculated using the ratio between the total of visits and the total number of attributed visits… 

Attribution: This term is used for storing in memory (by the use of a cookie), the fact that an Internet user has already visited a site from a campaign.