Best practices for offline events data

Your offline event data helps you understand how effectively your ads drive offline events. You can use this information to optimise your ad campaigns. Below are best practices for preparing and uploading your offline event data.

• Upload your offline event data with precise timestamps and use actual transaction values: Precise timestamps, including minutes and seconds, ensure that each unique event is included, such as multiple purchases made by the same person in one day. Actual transaction values allow you to see the most accurate event values in your reporting. You can see aggregated monetary value of your uploaded, matched and attributed events to better understand the return on your ad spend.
• Include an order ID field and enter a unique identifier for each transaction: Order IDs help deduplicate your offline events and improve attribution. Remember that each order ID should have a unique event time and customer associated with it. If you want to split a transaction into multiple events, you can also use the Item number field to provide unique item numbers for each event associated with the same order ID.

  Event name	Event time	Value	Currency	Order ID	Item number
  Purchase	2018-01-24T11:04:42	12	USD	13579
  Purchase	2018-01-24T11:04:21	24	USD	13580
  Purchase	2018-01-24T11:12:05	48	USD	13581	1
  Purchase	2018-01-24T11:12:05	24	USD	13581	2

• Upload offline event data regularly and in the order that the events occurred (sequentially by date): Regular uploads help minimise gaps in your reporting. We recommend that you upload daily so that offline data can be effectively matched against the performance of any ads you're running. The data you upload is processed in real time, so you can view results as soon as you add it.
• Only upload new data from the time of your last upload: Data is matched against tracked impressions within the last 90 days for events that occurred within 1, 7 or 28 days of an impression. If you've created an offline event set, but haven't uploaded any data within 90 days, you will then only have 35 days to upload content. Once you've uploaded content within 35 days, you will then go back to having 90 days to upload content. It's important to note that we recommend you upload your data as frequently as possible – daily would be ideal. Events that you previously uploaded can't be deleted and our system can only deduplicate events uploaded within a set period of time.
• Assign an event set to an ad account before you begin a campaign: An events set will track an account from the time it's assigned. Remember to enable auto-tracking when creating your offline event set so that any future ad campaigns in the account will automatically be associated. Keep in mind that auto-tracking isn't available for datasets. For a more automated process, you can also upload offline event data directly with the Conversions API, offline conversion API or partner integrations.