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title: "Conversion and Attribution Methodology"
canonical: "https://hub.freewheel.tv/space/BC/114425957/Conversion%20and%20Attribution%20Methodology"
format: markdown
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Overview Attribution is the process of determining if a conversion was caused by exposure to an ad, and assigning credit to a given ad or ads. Two common types of attribution include last click attribution and last view attribution. The last click method attributes a conversion to the last ad that user clicked on, and the last view method attributes a conversion to the last ad that user viewed. Buyer Cloud uses a combination of last click and last view attribution in reporting. Attribution There is no need to associate a conversion tag to a specific line item, as conversions are attributed at the advertiser, campaign, or line item level. A conversion tag can be linked to a click or impression from any line item within the advertiser. When a conversion occurs: In a desktop or mobile web environment, Buyer Cloud captures the  user_id  on the  conversion tag  via the cookie ID found in the header of the http call. In mobile apps, Buyer Cloud receives the  auction_id  or  device_id  in the  postback  call. Within the conversion’s lookback window, Buyer Cloud searches the advertiser's impression logs to find a matching click. For desktop and mobile web, it looks for a matching  user_id . For mobile apps, it searches for either a matching  auction_id  or  device_id . If matching clicks are found, the conversion is attributed to the most recent matching click within the conversion’s lookback window. If no matching click is found within the lookback window, but matching impressions exist, the conversion is attributed to the most recent matching impression within the conversion’s lookback window. Lookback Windows A lookback window is the time period during which an ad impression can be credited for a conversion. It's important to note that there are separate lookback windows for clicks and views. For example, if the click lookback window is set to 30 days and the view lookback window is set to 30 days, a user must complete a conversion within 30 days of either clicking or viewing an ad for the conversion to be counted. If the user clicks or views the ad and converts after 31 days, the conversion falls outside the respective lookback window and will not be attributed to that ad impression. Custom Attribution Buyer Cloud offers both real-time and batch log data to implement an attribution model using raw event data. Attribution requires both win logs and conversion logs. Win logs provide impression details, including  auction_id  and  user_id , while conversion logs capture all raw events, including  user_id  for desktop conversions and  auction_id  or  device_id  for postbacks. Conversion logs can be delivered in near real time or in batches, while win logs are always batched but delivered in near real time. Conversion logs for postbacks only include  auction_id  when the attribution provider has attributed a conversion to a specific  auction_id . To enable win logs and conversion logs, please reach out to your Account Representative.