What a Growth Agency Should Deliver in the First 90 Days

In the first 90 days, a growth agency should establish your starting numbers, launch tests, and show what the results change. Agree on those deliverables before work begins. Then you can judge progress against a plan instead of waiting for the agency to declare success.

Our checkpoints call for agreed starting measurements by day 14, a live experiment by day 30, and weekly learning reports by day 45. Day 90 brings a results review and a written plan for what happens next. The sections below explain the evidence to expect at each stage.

We use the same standards for ourselves. Still deciding whether to hire? Start with the readiness test for hiring a growth agency vs building in-house.

The short version: Agree on baseline metrics and access in the first two weeks. Launch a test by day 30, then expect regular learning reports before day 45. By day 90, the agency should explain what changed and propose a written next plan. Set these milestones before signing so both sides can judge the engagement on observable work.

What Should a Growth Agency Deliver in the First 90 Days?

A growth agency should establish baseline CAC and LTV by day 14, then launch the first experiment by day 30. Weekly reporting should start by day 45. By day 90, you should have a scaled winner and a written channel playbook. Those are the four checkpoints to agree on.

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.

Agree on that starting number early. Otherwise, month 3 reporting becomes a debate about what “improvement” means, when it should be a straightforward calculation.

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.

With the baseline agreed, creative is usually the first thing to test because it has the largest effect. 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.

What 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.

Use that playbook in the day-90 keep-or-fire review, which should be on the calendar before signing. Define what earns a renewal. For most teams, that means at least 1 channel or angle beating baseline with credible attribution, quick decisions to stop losing tests, and reports 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.

As you track those deadlines, also watch for these problems:

• 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?

Put the phases in writing before signing, and attach the table to the agreement. List the day-14 baseline, day-30 live experiment, and day-45 weekly learning report as deliverables. Then book the day-90 review on day 1 so the decision has a firm date.

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.

If you want help deciding what an agency should deliver in your first 90 days, we can work through the checkpoints together. Book a Free Strategy Call to discuss the baseline, first tests, and evidence your team should expect.