By the end of week 1, a good agency has already made you do work. They have requested ad account, analytics, and CRM access. They have asked for 12 months of spend data, your churn numbers, and intros to 2 or 3 customers they can interview. You feel slightly pestered. That is a good sign.
What week 1 usually looks like instead: a pleasant kickoff call, a recycled onboarding deck, and then quiet until the next scheduled check-in. The difference between those two week 1s predicts the whole engagement.
This is the accountability framework I would hand any founder signing with an agency, ours included. Put it in the contract conversation. If you are still deciding whether an agency is the right move at all, read the readiness test for hiring a growth agency vs building in-house first.
What Should a Growth Agency Deliver in the First 90 Days?
A growth agency should hit four checkpoints in 90 days. Baseline CAC and LTV math is due by day 14. The first experiment goes live by day 30. Weekly reporting starts by day 45. A scaled winner and channel playbook are due by day 90.
Here is the full checklist in one table.
| Phase | Deliverables you should see | Metric that proves it |
|---|---|---|
| Days 1 to 14 | Access secured, tracking audit, baseline CAC/LTV doc, ICP and message review | A baseline number you both signed off on |
| Days 15 to 30 | Prioritized roadmap, first creative or channel experiment live | At least 1 experiment launched against baseline |
| Days 31 to 45 | Weekly reporting, early learning, first kill or scale calls | Written decisions tied to experiment data |
| Days 45 to 90 | Winners scaled, incrementality check, written channel playbook | At least 1 channel or angle beating baseline |
| Day 90 | Keep-or-fire review with documented results | Your decision, made on data |
Notice what is not on the list: a brand refresh, a 40-page persona deck, or a promise that “results take 6 months.” Those are common, but they are not deliverables.
What Happens in Days 1 to 14?
Days 1 to 14 are for access, audit, and baseline math. The agency secures every account, audits your tracking and attribution, and produces a one-page baseline: current CAC, LTV or payback period, and conversion rates by funnel stage. They also pressure-test your ICP and messaging against real customer language.
The baseline document matters more than founders expect. Without an agreed starting number, month 3 reporting becomes a negotiation about what “improvement” means. With one, it is arithmetic.
A tracking audit usually finds something. In our work across $50M+ of managed paid media, broken or double-firing conversion events show up in most new accounts we open. Fixing that before test spend is often the cheapest win in the engagement.
The ICP review should use customer evidence rather than internal opinions. If the agency never asks to hear a customer’s voice, they are planning to advertise to a guess.
What Should Happen From Day 15 to Day 45?
The first experiment should be live by day 30. By day 45, reporting should be weekly and the agency should have documented early learning. The work may include creative tests against a control or a channel test justified by the diagnostic. The first kill-or-scale decision should already be visible.
Creative is usually the first lever because it moves the most. According to Nielsen’s research on advertising effectiveness, creative quality contributes 47% of sales impact, more than reach, targeting, or any other element they measured. An agency that tests audiences for weeks before testing a single new creative angle has the priorities inverted.
Expect the early reads to take 2 weeks or more per test, and be suspicious of anyone calling winners faster on thin data. Meta’s own documentation says an ad set needs about 50 optimization events to exit the learning phase. Budget and patience have to cover that, or every “result” is noise.
By day 45, the weekly cadence is non-negotiable. A dashboard link is not enough. Require a short written narrative: what ran, what it showed, and what changes next week.
Want this timeline as a structured engagement?
Use these checkpoints in any 90-day agency engagement. Set the baseline by day 14, launch the first experiment by day 30, review learning weekly by day 45, and require a 6 to 12 month roadmap by day 90.
Book a Free Strategy CallWhat Does Days 45 to 90 Look Like?
Days 45 to 90 are for scaling winners, checking that they are real, and writing it all down. Budget moves toward what beat the baseline. The agency runs at least a basic incrementality check, such as a geo holdout or a spend pause, to confirm the channel is driving new revenue rather than claiming credit for it. The phase ends with a written channel playbook.
The playbook is the asset that survives the relationship. It should document what was tested, what won and lost, the audiences and angles that work, and the next 2 quarters of priorities. You should own the learning whether you continue with the agency or take it in-house.
Then comes day 90, and this is the part founders skip. Put a formal keep-or-fire review on the calendar before you sign anything. Decide in advance what “keep” requires: for most teams, at least 1 channel or creative angle beating baseline with believable attribution, losers killed fast, and reporting you never had to chase.
What Are the Red Flags in Agency Onboarding?
The 3 biggest red flags are a strategy phase still running on day 60, no live experiment by day 30, and no weekly reporting by day 45. Each one means you are funding process instead of progress.
A few more worth watching:
- The deck is the deliverable. Strategy documents that restate your own onboarding answers back to you, with stock-photo polish.
- Metrics drift toward soft numbers. Reporting that leads with impressions and engagement when you are paying for pipeline.
- No kill decisions. An agency that never kills a test is either not testing or not telling you what failed.
- The team switched after the pitch. Senior people sold it, junior people run it, and your emails now get answered in 3 days.
Vague scope is usually the root cause, and it is set at signing, not at day 60. The questions in our breakdown of growth marketing agency pricing for SaaS (who staffs the account, what ships monthly, what metric reporting centers on) are the same questions that prevent most of these problems.
How Do You Hold an Agency to This Timeline?
Hold the agency to it by putting the phases in writing before you sign. Attach the table to the agreement. Name the day-14 baseline, day-30 live experiment, and day-45 weekly learning report as deliverables. Book the day-90 review on day 1.
Hesitation at that request is itself the answer. Good operators want a defined finish line because they expect to clear it.
A strong first engagement follows this exact structure because it replaces an open-ended retainer with clear checkpoints. Require a diagnostic, live experiments, and a roadmap you keep either way.
Still deciding whether to sign at all? Start with are growth agencies worth it, and if you are earlier stage, the seed to Series B agency guide maps the decision by funding stage.
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