A point forecast is a wish with a decimal. The operator's version triangulates three models that should disagree — then tracks its own error so it sharpens every cycle.
New here? Start with the 2026 measurement field guide.
A single number hides its assumptions and its uncertainty. Build a range, from three lenses:
"We'll do 9,000 subs next quarter" tells a CFO nothing about how or how sure. A point estimate buries its assumptions and erases its uncertainty — so when it misses, it reads as a failure instead of a known risk that came true. A range fixes all three problems at once: it surfaces the assumptions, makes the uncertainty explicit, and gives the business something honest to plan against.
Build the same forecast three different ways. They have different blind spots on purpose — so their agreement is signal and their disagreement is a map of your risk.
| Lens | How it's built | Best at | Blind spot |
|---|---|---|---|
| Bottoms-up funnel | Spend × conversion rates down the funnel to subs | Tying the forecast to controllable inputs | Assumes CVRs hold; misses saturation & market shifts |
| Top-down | Market size × share × seasonality & trend | Catching demand ceilings and seasonality | Too coarse to action; slow to see channel-level change |
| Cohort / LTV | Retention & expansion curves projected forward | Revenue durability and the installed base | Backward-looking; new-cohort behavior can shift |
Early on, the three lenses sit close — near-term momentum is hard to argue with. The further out you go, the more they fan apart, and the band between the lowest credible and highest credible lens is your forecast. Don't collapse it to a point; report the low / base / high and the assumption that separates them.
This is the lens you can actually steer, because every stage is a number you influence. Each conversion rate is an assumption you can defend — or that a skeptic can attack.
Read it top to bottom: spend buys installs at a cost per install, a share of installs become signups, a share of signups convert to paid, and a share of those retain. Change any one rate and the forecast moves — which is exactly why this lens is the one you manage to. Your low/base/high cases come from flexing the two or three rates you're least sure about.
You don't average the lenses — you assemble a range from them, and you treat disagreement as information rather than noise to be smoothed.
Usually the cohort/LTV view or a pessimistic funnel. This is your "we can commit to this" number — the floor you'd stake a plan on.
The consensus of the three, with your best-guess assumptions. This is what you publish as the plan.
Often the top-down view in a strong market. This is the "if things break our way" upside — useful for capacity and stretch planning, dangerous as a commitment.
When the funnel says 9,000 and top-down says 13,000, don't split the difference — find out why. Maybe the funnel hasn't priced in a seasonal tailwind; maybe top-down is ignoring a saturating channel. The reconciliation is where you actually learn something about the business. A tight range means you understand the quarter; a wide one tells you exactly what to go investigate.
The difference between a forecaster who gets better and one who repeats the same misses is a single discipline: logging forecast versus actual, every cycle.
Before the period, write down the low/base/high and the key rates behind them. A forecast you didn't write down can't be graded.
Bias = consistently high or low (a broken assumption). Variance = noisy both ways (genuine uncertainty). They demand different fixes — recalibrate the assumption vs. widen the band.
"We missed because paid CVR dropped from 10% to 8%." Now that rate gets more scrutiny next cycle. Misses with a named cause make the next forecast sharper; misses you shrug off repeat.
The triangulation framework this forecast borrows its logic from.
Read the field guide →The directional model that gives your funnel its saturation curves.
Read it →Response-curve optimization you can drive by hand.
Open the tool →How to choose the handful of clean tests you can run in a year.
Read it →If your number is getting questioned in the room — or you want a three-lens range instead of a single brittle figure — let's talk.
Last updated June 2026 · Part of an in-progress series on growth measurement & budget allocation.