How much traffic do I need to run a CRO test?

Enough conversions, not enough visitors. As a rough guide you need a few hundred conversions per variant to detect a realistic improvement with confidence. Low-volume sites are better served by qualitative research and heuristic fixes than by underpowered A/B tests.

Is CRO better than buying more traffic?

Often, because it improves the return on traffic you already pay for. Doubling conversion rate has the same effect as doubling ad spend, without the extra cost. The catch is that CRO gains are finite, while traffic growth compounds differently.

Web & CMS

CRO (Conversion Rate Optimization)

Conversion rate optimisation is the practice of improving a site or page so a higher share of visitors complete a desired action.

It uses data, testing, and user research to remove friction and strengthen offers, rather than simply buying more traffic. For example, clarifying a call to action or simplifying a form can lift conversions from the same visitors. It often delivers a better return than increasing ad spend.

The highest-return fixes are usually the least interesting ones. Forms that fail silently on mobile, a phone number that is not tappable, a checkout step that rejects Thai addresses, a call to action below three screens of copy. These are not tests, they are defects, and finding them is a matter of using the site the way a customer does on the devices customers actually have. Do that pass before designing any experiment, because a test comparing two versions of a page that is broken for a third of visitors will produce a clean result and no improvement.

Example

An insurer's quote form converts 2.1% of visitors. Session recordings show mobile users abandoning at the ID-card field; the error message was invisible on small screens. Fixing the message and cutting nine fields to five lifts conversion to 4.4%: 110% more quotes from identical traffic and spend. The equivalent growth bought as extra advertising would have cost 60,000 baht a month, forever.

Frequently asked questions

How much traffic do I need to run a CRO test?: Enough conversions, not enough visitors. As a rough guide you need a few hundred conversions per variant to detect a realistic improvement with confidence. Low-volume sites are better served by qualitative research and heuristic fixes than by underpowered A/B tests.
Is CRO better than buying more traffic?: Often, because it improves the return on traffic you already pay for. Doubling conversion rate has the same effect as doubling ad spend, without the extra cost. The catch is that CRO gains are finite, while traffic growth compounds differently.

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CRO (Conversion Rate Optimization)

Frequently asked questions

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