Seasonality

What This Page Answers

Seasonality is the predictable or event-driven change in demand, competition, conversion rate, inventory, and customer behavior over time. It affects budgets, bids, creative, landing pages, and interpretation.

Types Of Seasonality

  • Calendar seasonality

  • Holiday and retail peaks

  • Industry buying cycles

  • Weather or event-driven demand

  • Budget-year timing

  • Product launch timing

  • Promotional cycles

What To Watch

Seasonality can change:

  • CPM

  • CPC

  • CVR

  • AOV

  • ROAS

  • Inventory availability

  • Payback period

  • Creative fatigue speed

Use Why CPM Is High, Why ROAS Dropped, and Budget Allocation.

How To Diagnose It

Start by separating market seasonality from account-specific changes.

Market seasonality can show up as:

  • Higher CPM across multiple campaigns and platforms.

  • Higher search demand for seasonal terms.

  • Competitors increasing promotion volume.

  • Category-wide conversion rate changes.

Account-specific changes can show up as:

  • One campaign or audience changing while the rest of the account is stable.

  • Performance shifting after a budget, bid, creative, landing page, or tracking change.

  • Inventory, pricing, discount, or offer changes that affect only your business.

Use year-over-year comparisons when the business has enough history. Use week-over-week comparisons only when you label promotions, holidays, stockouts, launch dates, and tracking changes.

How To Plan Around It

Before a seasonal period:

  • Mark expected demand peaks in the reporting calendar.

  • Prepare creative and landing pages before CPM rises.

  • Separate testing budget from proven campaign budget.

  • Decide which metrics can temporarily move without triggering a false alarm.

  • Watch margin and payback, not only ROAS.

Practical Rule

Do not compare seasonal periods without context. Mark promotions, holidays, inventory changes, and tracking changes in reports.

Source Notes