How Media Forecaster builds a plan
How the reference period, baseline, optimized plan, actual to date, spend flexibility, and marginal return fit together in a Media Forecaster plan.
The numbers in a Media Forecaster plan come from four stages. You select a reference period. Media Forecaster builds the baseline from that period, recommends the optimized plan, and then shows your actual results to date. The baseline and the optimized plan are two forecasts of the same planning period. You compare the two forecasts with each other and with your actual results.
- You selectReference periodPast dates that set which media is eligible and the current spend of each row.
- Media Forecaster buildsBaselineThe reference spend mix, scaled to your budget and forecast over the planning period.
- Media Forecaster recommendsOptimizedThe budget moved between rows, inside your spend flexibility and limits, to reach your goal.
- So farActual to dateReported spend and modeled outcome so far in the planning period, paced against Optimized or Baseline.
Why does a plan have two periods?
Section titled “Why does a plan have two periods?”A plan has two periods because the two periods answer different questions. The reference period answers “what does current spend look like?”. The planning period answers “what dates is the plan for?”.
| Detail | Reference period | Planning period |
|---|---|---|
| Dates | In the past | From 14 days before today, or later |
| Sets | Which media is eligible, and the starting spend of each row | The dates that the plan allocates budget across |
| Effect on the forecast | Gives each row its share of the budget | Gives the forecast the seasonality of those dates |
The reference period does not limit what your models know. The models train on your full history. Which campaigns your models include is a different rule from which media a plan can use, and this page describes only the rule of the plan. The reference period only decides which media the plan can use and how much each row spends at the start. To be eligible, a campaign must have spent 100 or more, in your display currency, in the reference period. The campaign must also have a modeled metric for the goal of the plan.
Media Forecaster scales the reference spend to the length of the planning period. If the reference period is 30 days and the planning period is 90 days, the starting budget is the daily reference spend multiplied by 90.
A planning period can start as many as 14 days before today. The past days that have recorded spend cannot be planned, so the baseline and the optimized plan use the spend that was recorded on those days. The optimizer plans only the days that remain, with the budget that is left. For the rules, see Plan settings.
What is the baseline?
Section titled “What is the baseline?”The baseline is your reference-period spend mix, scaled to the budget of the plan. Each row keeps its share of reference spend. Media Forecaster forecasts the baseline with the same models, over the same planning period, as the optimized plan.
The baseline is the starting point of the plan, before the optimizer moves any budget. The optimized plan is measured against the baseline, so the lift in a plan is the difference between two forecasts of the same period.
What is the optimized plan?
Section titled “What is the optimized plan?”The optimized plan is the budget split that Media Forecaster recommends, and what the models forecast that split to deliver over the planning period. The optimizer moves budget between rows to reach your goal. What the optimizer does with the budget depends on the goal.
- Grow on a fixed budget: the plan spends the whole budget, so the optimizer only changes how the budget is split.
- Hit a target: with Set a ceiling, the optimizer spends up to your maximum budget, and less if the target is reachable for less. With Solve for it, your models find the spend that the target needs.
- Hold efficiency: the optimizer spends as much of your maximum budget as it can while the efficiency ratio stays at your target.
The optimizer works inside two kinds of constraint that you set.
- Spend flexibility applies to every row. It sets how far each row can move from its baseline, as a band such as 0.5× to 1.5×.
- An allocation type applies to one row. Max spend sets a ceiling, Min spend sets a floor, and Fixed takes the row out of the optimization.
A wider band gives the optimizer more room to improve the plan. A wider band also makes the plan depend more on the response curves of your models. Above 2× of the baseline, the plan relies on extrapolated curves, so the results are less certain.
Spend flexibility changes how the budget is split. Spend flexibility does not change the total budget.
What does the marginal column measure?
Section titled “What does the marginal column measure?”The marginal column measures the modeled return from the next unit of spend at the recommended spend. A row-level average tells you how the whole budget of a row performs. The marginal value tells you how the next dollar performs.
- For a return metric such as ROAS, the marginal value is the modeled return from the next $1.
- For a cost metric such as CAC, the marginal value is the modeled cost of one more result.
The name of the column depends on the goal of the plan. Whether your account sees a return metric or a cost metric depends on your models.
What is actual to date?
Section titled “What is actual to date?”Actual to date is what happened so far in the planning period: the spend that your reporting recorded, and the outcome that your models attribute to that spend. Baseline and optimized are forecasts. Actual to date is not a forecast, but its outcome is a modeled value, so it can differ from the number in your store or ad platform.
When you compare actual results with a plan, you choose what to compare against.
- Optimized plan or Baseline plan selects the forecast.
- Expected to date or Full plan period selects the span.
Expected to date adds up the values of the plan for each period through today. This follows the shape of the plan. A plan that spends more in later periods is not compared with an even daily split.
How do Optimization and Forecast plans differ?
Section titled “How do Optimization and Forecast plans differ?”The plan type sets the level of detail that the plan works at.
| Detail | Optimization | Forecast |
|---|---|---|
| Works on | Your live campaigns | Your channels and tactics |
| Best for | The next few weeks | Longer horizons |
| Spend flexibility applies to | Each campaign | Each tactic or channel |
| Campaign tab in results | Yes | No |
| Solve for it, for a goal in the Hit a target family | Available | Available |
| Shortest feasible | Available with Solve for it | Not available |
Media Forecaster suggests Forecast for a planning period of 42 days or more.
Why are the settings of a finished plan locked?
Section titled “Why are the settings of a finished plan locked?”The settings of a finished plan are locked because the results depend on the settings. A change to the budget, the dates, or the media produces a different plan. To change a setting, duplicate the plan and run the copy. The original plan and its results stay as a record.