View Attribution is one of the ways Meta gives credit to an ad for a conversion. The default Attribution Setting is 7-day click and 1-day view, meaning that conversions will be attributed for anyone who converted within 7 days of clicking or 1 day of viewing (without clicking) your ad.
View-Through conversions are most difficult to verify from third-party sources since a click never happens.One common scenario where this happens is when someone views your ad and later Googles your product and converts. Another example is when you reach a user through remarketing who also receives an email from you and they act on that email within one day.
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