Most media plans answer the wrong question. They document where spend goes - a tidy split across Meta, Google, TikTok, and the rest - without ever justifying it. The result looks rigorous but cannot be defended, because nobody can say why the budget is divided that way rather than any other. A plan built this way is a statement of intent dressed up as analysis. The framework below treats a media plan as an argument: every allocation is a claim about expected return, and the plan’s job is to make that claim explicit, testable, and revisable. If you have been doing this in spreadsheets, it is worth understanding why media planning without spreadsheets produces plans that hold up under scrutiny.
Step 1: Set objectives
Begin with the commercial outcome the plan must deliver, expressed as a single primary objective with explicit constraints. Revenue at a target ROAS, a fixed number of leads at a maximum CPA, or growth within a capped budget are all valid - what matters is that the objective is unambiguous, because every later decision is ultimately judged against it. A vague goal such as “grow awareness” cannot adjudicate between two budget splits; a concrete one such as “1,200 qualified leads at or below £45 CPA this quarter” can. Setting the objective first also forces an honest conversation about whether the budget is sufficient to reach it at all.
Step 2: Select channels
Choose channels by the distinct role each one plays in reaching and converting the audience, not by habit or by spreading budget evenly to look diversified. Some channels capture existing demand - branded search harvests intent that already exists - while others create it. A plan that funds five channels which all do the same job is less robust than one that funds three channels covering discovery, consideration, and conversion. Ground these choices in audience reach and the commercial model you are working within, whether that is ecommerce or lead generation, so the channel mix reflects how value is actually created in your business.
Step 3: How should you allocate the budget?
Allocate spend by the expected marginal return of each channel rather than its blended historic average. This is the single decision that separates a defensible plan from a flattering one. A channel showing a strong average ROAS may already be saturated, meaning the next pound invested in it returns far less than the average implies - while a smaller channel with a lower average may still be on the steep part of its response curve and able to absorb more spend profitably. Allocating on averages systematically over-funds harvesting channels and starves growth channels. The distinction between marginal ROAS and average ROAS is the foundation of this step, and a budget allocation simulator lets you test where the next pound works hardest before committing it.
Step 4: Forecast performance
Once budget is allocated, forecast the outcome before any money is spent. A forecast turns the plan from a statement of intent into a testable prediction: given this allocation, here is the revenue, lead volume, or CPA we expect, and here is the uncertainty around it. Crucially, the forecast must account for diminishing returns - every channel has a point beyond which extra spend buys progressively less, the dynamic captured by saturation curves. Forecasting before you spend is the core of ElenIQ’s approach, and an ad spend forecasting tool lets you project results across the full allocation rather than guessing channel by channel.
Step 5: Plan scenarios
A single forecast is fragile because budgets rarely land exactly as planned. Build several scenarios - what happens if the budget is cut by twenty per cent, if it grows, or if spend shifts from a saturated channel into one with headroom - so you understand the shape of the outcome rather than a single point estimate. Scenario planning reveals which decisions the result is sensitive to and which barely move the needle. It also gives stakeholders something concrete to react to: instead of approving one number, they can see the trade-offs and choose the allocation that best fits the business’s appetite for risk and growth.
Step 6: Document risks and assumptions
Every forecast rests on assumptions - that historic response curves still hold, that creative performance is stable, that no major seasonality or competitive shift is imminent. Write these down, alongside the risks that could break the plan, so the forecast can be interrogated rather than taken on faith. A plan that hides its assumptions invites overconfidence; a plan that surfaces them invites scrutiny, and scrutiny is what makes a forecast trustworthy. When results diverge from the plan, documented assumptions are also what let you diagnose why - and update the model rather than abandon it.
Step 7: Explain the forecast rationale
Finally, articulate the causal logic that links each allocation decision to the expected outcome. This is the step most plans skip and the one that defines a good plan: a reader should be able to follow why the budget is split the way it is, why one channel received more than another, and why the forecast lands where it does. When the rationale is explicit, the plan can be defended in front of a sceptical stakeholder and revised intelligently when conditions change. For agencies presenting plans to clients, this transparency is what builds trust - which is why paid media forecasting for agencies centres on explaining the reasoning, not just delivering the numbers.
Frequently asked questions
What is a media plan?
A media plan is a structured allocation of advertising budget across channels, audiences, and time, together with the reasoning behind each decision. A strong media plan explains not only where spend goes but why that allocation is expected to outperform the alternatives, what return it should produce, and what assumptions it depends on.
How do you create a media plan?
Set a clear commercial objective, select channels by the role each plays, allocate budget by expected marginal return rather than historic average, forecast performance before committing spend, build alternative scenarios, document the risks and assumptions, and explain the rationale behind the allocation. The plan is finished when a stakeholder can read it and understand why the money is split the way it is.
What makes a paid media plan good rather than just complete?
A complete plan lists channels, budgets, and targets. A good paid media plan goes further and justifies them: it shows the forecasted outcome of the allocation, demonstrates that budget sits where marginal return is highest, and makes its assumptions and risks explicit so the plan can be challenged and improved rather than accepted blindly.
Why allocate budget by marginal return instead of average ROAS?
Budgets are spent at the margin, so the decision that matters is what the next pound of spend will return, not what the channel returned on average last quarter. Average ROAS hides saturation, which causes plans to over-invest in channels that look efficient but have stopped scaling and under-invest in channels with room to grow.
Should a media plan include forecasts and scenarios?
Yes. A forecast turns a media plan from a statement of intent into a testable prediction, and scenarios show how the outcome changes if budgets shift. Forecasting before you spend is what lets you compare allocations, set realistic expectations, and identify the point at which extra budget stops paying for itself.