# Optimizing Spend Requires Measuring Incremental Outcomes Not Reach ## Claim Optimizing a marketing budget is meaningless without measuring incremental outcomes, because reach metrics can rise while the real effect stays flat. <!-- atomicity: 1 idea ✓ --> ## Scope & conditions - Holds for any program spending to grow an audience — events, DevRel, content marketing — where the same people can be re-reached without new people being added. - Requires a way to distinguish new participants from returning ones (a "how did you hear" question, a control group, or comparable); without that instrument the claim is true in principle but not actionable. - Weakens where the audience is small enough, or the spend small enough, that any incrementality signal is swamped by noise — the WordCamp source itself flags this ($400 may be too small to move a detectable needle). ## Evidence The WordPress Community Team's post on WordCamp advertising grants states plainly it has no way to know whether the up-to-$400 ad spend "is bringing in new faces, or reaching the same people who were already coming" — allocation guidance exists, effectiveness data doesn't. Their proposed fix is a mandatory ticket-screen "how did you hear about this event?" question plus a post-event organizer channel survey, explicitly framed around incrementality (net-new attendance) rather than raw reach. ## Links - [[3. Resources/Permanent Notes/A Metric Is Vanity Only Against Your Own Outcome Data]] — because extends; that note gives the general test (regress against your own outcome data before calling anything vanity), this note supplies the specific outcome metric — incrementality — that event and DevRel spend should regress against - [[3. Resources/Permanent Notes/The Four Objectives Framework Replaces Vanity Metrics in DevRel]] — because applies-in; incrementality is the sharper version of "outcome over reach" inside that framework's Awareness stage specifically - [[3. Resources/MOCs/DevRel MOC]] — because applies-in; this is DevRel's perennial attribution problem, instantiated in a $400 event grant ## Tests / falsifiers - Compare WordCamps that add a "how did you hear" ticket question against those that don't: does self-reported channel data actually change budget allocation decisions, or does it get collected and ignored? - Track whether any WordCamp with above-median ad spend shows above-median new-attendee share (vs. returning-attendee share) once the data exists — if spend doesn't correlate with new-attendee share even directionally, the incrementality framing itself needs revisiting for this program. ## Maintenance - Last tended: 2026-08-16 - Next review: 2026-11-16 ## Source - [[3. Resources/Readwise/Full Document Contents/Articles/How Effective Are Our Advertising Efforts for WordCamps]] — states the current measurement gap and proposes the ticket-question and organizer-survey instruments, asking for organizer/attendee input before building.