# Should a Campaign Banner Show a Countdown Timer?

Page: https://alidemirbas.com.tr/en/lab/ab-test-library/tests/should-a-campaign-banner-show-a-countdown-timer

## Hypothesis

If the campaign banner shows how much time is left before the real end of the offer, interested shoppers may decide before it expires instead of putting the purchase off. The campaign purchase conversion rate could go up as a result.

## When to run this test

Visitors leaving without buying after a banner click, orders piling up right before the campaign ends, or support tickets asking when the offer ends point to a banner that draws interest while purchases get postponed. If the countdown cuts that delay, shoppers buy the campaign product without waiting for the deadline and complaints about the timing do not rise. Run the test only for a campaign with a real end date that will not move during the test; if shoppers misunderstand the offer itself, look at that first.

## Primary metric

**Campaign purchase conversion rate**: Compare campaign purchases among visitors assigned to the countdown banner.

## Other metrics

- **Campaign banner click-through rate**: Track banner clicks, but do not treat them alone as purchase success.
- **Campaign page exit rate**: Compare exits among visitors who view the campaign page.
- **Campaign gross margin**: Compare gross margin on campaign orders between the arms.
- **Campaign-related complaints**: Track reports that the timing or offer was unclear or inaccurate.

## What to check before and during the test

- **End-time display**: Add a countdown tied to the campaign's actual end time.
- **Keep constant**: Keep discount, eligibility, banner copy and placement unchanged.
- **Accuracy**: End the offer when the timer expires; do not reset the countdown for returning visitors.
- **Audience**: Review new and returning visitors as secondary segments.
- **Separate tests**: Test countdown placement or time format separately.

## What to watch when reading the result

- More banner clicks alone do not show that the countdown works; the campaign purchase conversion rate is what counts. If purchases rise while campaign gross margin falls or campaign-related complaints grow, hold off on shipping.
- Limit this result to this campaign and this banner on the listing page; validate it again before applying it to another campaign or page. Read new and returning visitors separately, and check that returning visitors see the same deadline and that repeat visits do not drop.
- Because the campaign has a fixed end, the test cannot run longer than the campaign. Before launch, get the sample needed per variant from the [sample size calculator](https://alidemirbas.com.tr/en/calculators/sample-size-calculator) and compare it with the eligible visitors each arm will get during the campaign; if the campaign falls short, do not treat a small difference as a result, and repeat the test in the next real campaign.
- Visitors should be able to dismiss the countdown, and it should not cover the main page content. If the timer cannot be closed or hides content, do not read the resulting difference as the effect of showing the deadline; watch the campaign page exit rate with that in mind.

## Frequently Asked Questions

### Which deadline should the countdown use?

Use the campaign’s real deadline. The offer and timer must end together, and a return visit must not reset the clock. Use the campaign-product purchase rate as the primary outcome.

### Do more banner clicks prove the countdown worked?

No. Clicks are diagnostic, not completed campaign purchases. Monitor campaign gross margin because additional sales can have a different margin mix.

### How should a countdown appear on mobile?

Keep it readable without covering the CTA. For non-essential automatically updating content, provide the applicable pause, hide or update-control mechanism. Do not change the real deadline. Monitor campaign complaints and consider WCAG’s essential-activity exception.