Sales forecasting for Shopify merchants

Find the levers that grow your revenue

Diamond Forecast Agent projects your Shopify sales for the next 52 weeks in one click, and measures which growth levers (discounts, social media and more) are moving it. Update your forecast without complex spreadsheets or dashboards, simply describe your plan in plain English.

How the forecast works

A Prophet model, fitted per collection

We fit Meta's open-source Prophet model to each collection's weekly sales history and project 52 weeks ahead. We use Prophet because it is easy to understand, not a black box, and easy to customize. Prophet breaks revenue into parts you can read on their own and adds them together:

y(t)=g(t)+s(t)+Σ β·x(t)

Forecast = Trend + Seasonality + Growth Lever Regressors. Collections with fewer than 12 weeks of sales history are excluded, because Prophet can't generate a valuable forecast from so little data.

JanAprJulOctDec

Trend

g(t)

Piecewise linear growth. Prophet places changepoints where the growth rate shifts (the dashed line) so a slow spring doesn't flatten the whole year.

JanAprJulOctDec

Seasonality

s(t)

A day-of-year pattern learned from past years, like a strong start to the year, a summer slowdown and a pickup in the fall.

JanAprJulOctDec

Regressors

Σ β·x(t)

Growth levers enter as extra regressors: discount %, whether social traffic from Instagram, Facebook or YouTube was active and generating orders, plus any custom lever you add.

JanAprJulOctDec

Confidence interval

Each forecast carries a 80% band built from simulated trend changes and observation noise. It widens the further out you look.

Forecast

Cumulative within each calendar year · revenue in USD · all collections

Actual Forecast 1 — baseline Forecast 2 — planned campaigns Forecast 1 80% confidence Forecast 2 80% confidence

Forecast 1 is the baseline: no discounts, no social media traffic generating orders. It shows where revenue is heading on trend and seasonality alone.

Forecast 2 adds your planned campaigns: discounts, social media and custom levers (e.g. newsletters).

How growth levers work

Weekly lift per lever, per collection

A growth lever is anything you do that might change revenue. Because each lever is a regressor in the model, we can compare the forecast with the lever on and off and read the difference as its weekly revenue lift, with a confidence band around it. Like the trend and seasonality, each lever's effect is estimated from your store's historical data.

Discounts

Default

Discount % per collection per week, read from your order history. Lift is measured as e.g. 10% vs 0%.

Social media traffic

Default

Whether traffic from Instagram, Facebook or YouTube was active and generating orders that week. Lift is active vs inactive.

Custom levers

Optional

Newsletter campaigns, affiliate campaigns, trade shows: any dated activity can become a lever. Ask in chat or attach a schedule.

Reading the chart

The tick is the estimated lift; the bar is its 80% band. A band clear of $0 (blue) is an effective lever. A band that crosses $0 (grey) means the data can't tell. These are associations, not proven cause and effect.

Growth levers

Weekly revenue lift estimates with 80% confidence band · association, not proven cause and effect.

How the agent works

Change the plan in plain English

Tell the agent what you're planning. It turns your message into new forecast parameters, re-runs the forecast with these, and replies with what changed and how the projection moved. Every change is logged and accessible in your session history.

Forecast agent Session ID: 14 · ends 9/21/2026, 4:08:20 PM PDT
Active
Assume 10% discount the week of Black Friday
Forecast agent9/16/2026, 10:31:34 AM PDT
Changes applied
10% discount added for all 5 collections for the week of Nov 23–29 (Black Friday) in Forecast 2.
See full assumptions in Settings →
Forecast agent9/16/2026, 10:31:34 AM PDT
Updated Summary

Forecast 2 now includes a 10% discount during Black Friday week. Compared with the baseline Forecast 1, the discount adds an estimated $540 that week (80% band $310–$770).

Describe a change in plain English — discounts, social campaigns, newsletter sends, trade shows...
Attach Send

Discounts

Add or modify discount values and schedules, for all collections or one. Example: “Assume 10% discount the week of Black Friday”

Social media

Add or modify social media conversions by week. Example: “Assume social media traffic is active and driving orders in December”

Custom levers

Add or modify any dated activity, past and future, by describing it or attaching a newsletter, trade-show or campaign schedule (CSV, XLSX or PDF). The agent backfills history so the model can learn the lever's effect. Example: “I've been sending newsletter on the first week of every month for the past year, and will continue until end of year. Include this in the forecast”

Support

Questions or Feedback

Email us at support@diamond-analytics.com