Definition
Reach is the number of unique people who saw your ads over a period.
Example
If 120,000 unique users saw your ads in a week, weekly reach is 120,000.
How to use it
- Use reach with frequency to understand how saturated an audience is.
- High reach with low frequency usually means you still have room to scale.
- Compare reach by segment (prospecting vs retargeting) to avoid mixing intent.
Common mistakes
- Treating reach as guaranteed exposure (it can include low-quality placements).
- Comparing reach across platforms without aligning time windows.
Why this matters
This term matters because it affects how you interpret performance and make budget decisions. If you use inconsistent definitions or windows, ROAS/CPA can look "better" while profit gets worse.
Practical checklist
- Write a 1-line definition for "Reach" that your team will use consistently.
- Keep the time window consistent (weekly/monthly/quarterly) when comparing trends.
- Segment results (channel/plan/cohort) before drawing big conclusions from blended averages.
- Sanity-check with a related calculator from the same category on MetricKit.
- Read the related guide (e.g., Frequency and creative fatigue: diagnose performance decay and fix it) for context and common pitfalls.
Where to use this on MetricKit
Calculators
- Paid Ads Funnel Calculator: Model CPM -> CTR -> CVR to estimate CPC, CPA, ROAS, and profit per 1,000 impressions (with margin and variable costs).
- ROI Calculator: Calculate Return on Investment (ROI) for a campaign or project.
- Incrementality Lift Calculator: Estimate incremental conversions, incremental ROAS, and incremental profit from a holdout test.
- Marginal ROAS Calculator: Estimate diminishing returns and find the profit-maximizing ad spend from a simple response curve.
- Target CPA from LTV Calculator: Translate LTV and contribution margin into a target CPA (and break-even CPA) for paid acquisition.
Guides
- Frequency and creative fatigue: diagnose performance decay and fix it: Learn how frequency, reach, and impressions interact with CTR/CVR, when to cap frequency, and how to refresh creatives without tanking learning.