View-Through Rate (VTR) captures the value of ad VIEWS rather than clicks. It's used where clicking is impossible or unnatural — [[ctv]], pre-roll video, and other lean-back formats. Depending on context it means either the video completion rate (the share of viewers who watched the ad to the end) or the view-through conversion rate (the share who saw the ad and later converted without ever clicking).
View-through vs click-through
Two ways an ad gets credit
| Signal | Trigger | Strength |
|---|---|---|
| Click-through ([[click-through-rate]]) | User clicks the ad, then converts | Strong — explicit intent |
| View-through (VTR) | User sees the ad (no click), then converts within a window | Weaker — exposure, not action |
View-through is essential for non-clickable inventory but easy to over-credit: a view "preceding" a conversion isn't proof it caused it.
Use it carefully. Because a view is exposure rather than a deliberate action, view-through attribution can inflate a channel's apparent contribution — some of those users would have converted anyway. Mature programs cap view-through windows tightly and validate the channel with [[incrementality]] testing, treating VTR as directional rather than as last-click truth.