Most digital projects end with a launch. The agency delivers, the client signs off, and both parties move on. Three months later the client isn't sure if anything changed, and the agency has no idea either.
We've been on both sides of this dynamic. It's not satisfying for anyone. So several years ago we introduced a mandatory KPI agreement at the start of every project. It takes 90 minutes to complete. It changes how every decision gets made from there.
Why defining success upfront changes everything
When you agree on KPIs before starting:
- Design decisions have a measurable criteria: "will this increase conversion rate?" beats "do we like this design?"
- Scope disputes have a neutral ground: "does this feature move the agreed KPI?" cuts through subjective debates
- Launch day feels like a beginning, not an end — both parties know what 30/60/90 day success looks like
- Post-launch work has clear direction: we know which metrics to improve and what to test next
The KPI categories we use
Revenue & pipeline impact
- Number of qualified leads per month — baseline vs. 90-day target
- Revenue attributable to organic web traffic — tracked via UTM parameters
- Sales cycle length — does better collateral shorten the decision process?
- Average deal size — for e-commerce: average order value
Funnel performance
- Homepage → contact form conversion rate — measured via GA4 events
- Landing page conversion rate — for campaign pages, target set per campaign
- Cart abandonment rate — for e-commerce, tracked via checkout funnel
- Form completion rate — how many users who start a form finish it
Performance & quality
- Core Web Vitals — LCP <2.5s, FID <100ms, CLS <0.1 (we target all green)
- Lighthouse Performance score — our standard: 90+ mobile, 95+ desktop
- Mobile page load time — target <2s on 4G connection
- Uptime SLA — 99.9% minimum, monitored post-launch
User behavior signals
- Bounce rate on key pages — homepage, pricing, key landing pages
- Average session duration — proxy for content relevance and UX quality
- Pages per session — especially relevant for multi-product or content-heavy sites
- Return visitor rate — for products and platforms: retention health signal
The KPI agreement format
We document it as a one-page table: KPI name, current baseline value, 30-day target, 90-day target, measurement method, and owner. Two columns: ours (technical KPIs) and theirs (business KPIs). Both parties sign off.
This document becomes the north star for the project. When a stakeholder asks "can we add this feature?" the question becomes "does this feature move any of the agreed KPIs?" If yes — it's worth scoping. If no — it goes in the backlog.
Agreeing on KPIs before starting a project is the single most effective thing we've done to reduce scope creep, improve client satisfaction, and build long-term relationships. It turns a transaction into a partnership.
If your current agency has never asked you how you'll measure the project's success — that's worth paying attention to. It might not be a process gap. It might be an accountability gap.