Impressions are the total number of times your ad was delivered. If 500,000 devices each see your ad twice, your impressions are 1,000,000. Reach is the number of unique devices (or ideally, unique people) exposed at least once — in this example, 500,000. Frequency is the average number of times a reached device saw the ad: impressions ÷ reach = 2. These three metrics are related: Impressions = Reach × Frequency. Understanding this relationship matters for campaign planning — a fixed budget deployed with high frequency burns on a small reached audience, while broad reach with low frequency trades off awareness depth for breadth.
On India CTV, these metrics have specific measurement quirks. Reach is measured at the device level, not the person level — one CTV device serving a four-person household counts as one reached device. Frequency caps in DSPs apply per device ID, meaning the household sees the ad the capped number of times across all its viewers. Cross-publisher reach is not deduplicated — if you run on JioCinema CTV and YouTube CTV simultaneously, each platform reports its own reach figure, and the true unduplicated cross-platform reach requires third-party measurement not yet standardised in India. Most India CTV campaigns report impressions and VCR as primary delivery metrics, with reach available from publisher reports but not audited by independent third parties.
Full guide
For a complete explanation, read: Impressions, reach, and frequency in CTV: what the numbers actually measure