What is a view-through conversion, and should you count it?
A view-through conversion is one credited after someone saw your ad without clicking it, within the platform's view window, which defaults to one day on Meta. It reflects something real, since ads can influence a purchase without a click. It is also the easiest place for a platform to credit itself with a sale it did not cause, because the qualifying event is simply that an impression was served.
Both major platforms count them, with different defaults. Meta's standard attribution setting is seven-day click and one-day view, so a purchase within a day of an impression is attributed to the ad even with no interaction at all. Google reports view-through conversions separately for Display and video campaigns. The mechanism is legitimate, and for upper-funnel video or display work, ignoring view-throughs entirely will understate the channel.
The reason to treat them with suspicion is structural rather than a matter of platform honesty. A campaign that serves large volumes of impressions to people who are already close to buying, retargeting being the clearest case, will accumulate view-through conversions in direct proportion to how many impressions it served to that audience. The correlation is guaranteed by the setup, so a strong view-through number is consistent with the campaign causing a great deal and with it causing nothing at all. The metric cannot distinguish between those two worlds.
So report click-through and view-through separately, never as one blended total, and be openly sceptical of any campaign whose case rests mainly on view-throughs. When it matters enough to argue about, the argument is not winnable from the reporting: withhold the campaign from a comparable group and measure what changes.