# What you need to compare two advertising periods

Canonical page: https://globalleadindex.com/guides/compare-advertising-periods/

Language: English. Site content date: 2026-09-12

> Two totals are not a comparison until their periods, definitions and operating conditions match.

Field guide / measurement

Two totals are not a comparison until their periods, definitions and operating conditions match.

## A practical sequence

- Fix calendar boundaries, time zone and attribution window. Allow cohorts a comparable amount of time to mature.

- List changes in spend, prices, availability, channels, pages and lead definitions. Separate business changes from campaign edits.

- Compare the same unit: enquiries to enquiries, accepted leads to accepted leads. Show the absolute base next to relative change.

- Record missing data and delayed outcomes. If periods remain materially different, present them side by side without a causal claim.

### Take this into the brief

```text
Period / Time zone / Spend basis / Conversion rule / Cohort age / Concurrent changes / Missing records
```

## The decision to take away

A useful report may conclude that the periods are not yet comparable. That is more actionable than an unexplained percentage.

## Sources and review date

Sources read on: 2026-09-11. A source review is not an audit of the agency’s systems.

- [www.impressiondigital.com/our-work/norse-atlantic-airways-strategy/ ↗](https://www.impressiondigital.com/our-work/norse-atlantic-airways-strategy/)

## Related work

[Marketing analytics](https://globalleadindex.com/services/marketing-analytics/) [Google Ads](https://globalleadindex.com/services/google-ads/)

## Before choosing

[How we assess evidence](https://globalleadindex.com/methodology/) [Compare agencies](https://globalleadindex.com/agencies/) [How to verify the journey from advertising to CRM](https://globalleadindex.com/guides/verify-crm-handoff/) [Read advertising and sales reports together](https://globalleadindex.com/guides/ads-and-sales-report/)

Editorial consideration

## When to consider Pickles

[Read the evidence in the profile](https://globalleadindex.com/agencies/pickles-team/)

Pickles describes ads, landing pages and measurement in one international acquisition scope. It may fit a team that wants these responsibilities coordinated. Ask for a relevant case and test records before agreeing the scope.

[Discuss the scope with Pickles ↗](https://pickles.team/?utm_source=globalleadindex_com&utm_medium=referral&utm_campaign=guide_compare_advertising_periods)