seasonal-budget-planner

name	seasonal-budget-planner
description	Plan ad budgets around seasonal peaks — holiday scaling, CPM inflation, pre-season/peak/post-season phasing, and Smart Bidding seasonality adjustments. Use when a user wants to plan Black Friday or holiday budgets, forecast peak-season costs, or build a seasonal campaign calendar.

Seasonal Budget Planner

Peak season punishes flat budgets twice: CPMs inflate 50-150% while unprepared accounts pay them with untested creative and cold audiences. Plan in phases, not in a panic the week before.

Ground the plan in your own history first: pull_<platform>_ads_performance over last year's season and ga4_run_report with a date dimension to see your real demand curve.

1. Plan in four phases

• Pre-season (6-8 weeks out), 70-80% of normal budget: build remarketing pools, A/B test creative so winners are proven before CPMs spike (see creative-testing), verify tracking (see conversion-tracking).
• Ramp-up (2-4 weeks out), 100-120%: scale winning creative, run teasers, warm audiences, pre-load promo assets.
• Peak (event days), 200-500% of normal daily budget: all prepared campaigns live, aggressive bids, budget weighted to warm retargeting audiences, urgency messaging, hourly monitoring.
• Post-season (1-4 weeks after), 80-100%: retarget peak-period visitors who did not convert, extended-sale and clearance messaging, step bids down as competition fades.

2. Budget for CPM inflation

Costs are not flat across the year. Against a January baseline, expect roughly 1.2-1.3x by September-October, 1.5-2.5x in November, and 1.4-2x through mid-December, with event spikes around Prime Day and Back-to-School. Practical moves:

• Front-load: early-November impressions cost far less than BFCM-week impressions.
• Shift flexible spend into January and April, the cheapest months.
• During peak weeks, tilt toward retargeting and search, where you pay for intent rather than inflated reach.

Use forecast_campaign to sanity-check projected volume at planned budgets before committing.

3. Index the budget to your industry curve

Build a monthly index from your own trailing 12-24 months of performance data (100 = average month), then set each month's budget as baseline x index/100. Ecommerce typically peaks November-December and troughs in summer; B2B peaks January, March, and September-October and dies in late December; fitness and education have their own January and August-September spikes. Your data beats any generic table — pull it before assuming.

For B2B specifically: push hard in January (new budgets), March (Q1 use-it-or-lose-it), and September-October (next-year budget finalization); cut 30-40% in July-August and after December 15.

4. Use platform seasonal features

• Google Seasonality Adjustments tell Smart Bidding to expect a temporary CVR change for 1-7 day events (flash sales, BFCM). Set +30% for a general holiday, +50% for a major sale, up to +100% for a deep-discount flash sale, about 24 hours before the event. Do not use them for gradual trends; Smart Bidding learns those itself. See platform-google.
• Promotion extensions and countdown customizers on Google; Advantage+ shopping on Meta (see platform-meta).

5. Anchor to the event calendar

The big cost spikes are predictable. Plan phases backward from the dates that matter for the vertical:

• BFCM (late November): the peak of peaks, +80-150% CPMs across retail.
• Christmas (Dec 1-24, peaking mid-month): +50-100%, then a hard drop after Dec 20.
• Prime Day (mid-July): +40-60% around Amazon, spillover elsewhere.
• Back-to-School (Aug-Sep): +20-30% for electronics, apparel, supplies.
• Gift holidays (Valentine's, Mother's/Father's Day): +15-30% in gifting categories for the surrounding week.

If you are not in the category, these are your cheap weeks — competitors' budgets left the auction.

6. Execute and guard

Encode the phased plan with create_campaign_plan and execute_campaign_plan, apply phase changes with update_campaign_budget, and rebalance across platforms mid-flight with optimize_budget. Set set_spend_alert before peak so a 5x daily budget cannot silently run for a week. During peak, review daily with pull_<platform>_ads_performance; after, reconcile what each platform claims against site truth with reconcile_platforms.

Rules

• No creative testing during peak. Test in pre-season; peak runs proven winners only.
• Higher CPMs are acceptable only where CVR rises to match. Track CPA/ROAS through the spike, not spend.
• Budget increases in steps, not cliffs — large jumps reset bid-strategy learning right when you need it stable (see bid-optimization).
• Write down actual vs planned after the season. Next year's plan starts from this year's miss.
• For the year-round allocation question underneath the seasonal one, use mmm-budget-planner and media-plan.