CRO experiments

What it does

Nexus reads the client's Google Analytics 4 data page by page and finds the pages with a lot of traffic and few conversions (or low engagement). For each page it writes 3 to 5 test ideas. Each idea has:

• what the numbers show,
• the hypothesis and the exact change,
• variant copy in the client's voice: a headline, a call to action and a proof block,
• the metric that decides it (the share of sessions that convert) and a guardrail metric,
• how many sessions and days the test needs to show a real difference. Nexus calculates this from the page's traffic; it is not a guess.

The ideas land in a Google Doc in the client's CRO folder, and each one gets an id.

Nexus does not split traffic and does not change the page. A person makes the change in the CMS or in a testing tool such as Optimizely or VWO. Nexus then judges the change: it compares the page's conversion rate for the same number of days before and after the change. That is a before/after comparison, so seasonality and campaigns can move the number too.

Set it up

• GA4 must be connected (see the Search Console and Analytics guide).
• Conversions in GA4 must be marked as key events (a form submit, a demo request, a purchase). With no key events, Nexus picks pages on engagement and says so.
• Optional: run a visual audit of the page first (see the website launch QA guide). The CRO ideas use that audit when it is on file.

Use it

1. "What should we A/B test on the site?" Nexus picks the pages and writes the ideas.
2. "CRO ideas for the pricing page." The same, for one page you name.
3. Make one change live. Your Nexus team then starts tracking it as an experiment.
4. After the test window: "Did the CRO test work?"

Results

Each experiment ends with one verdict:

• Helped or hurt: the conversion rate moved, and the move is statistically significant.
• No change: the page got enough traffic to see a real lift, and there wasn't one.
• Inconclusive: too little traffic or too few conversions, a page with no conversions before the change, or a lift that came with a drop in the guardrail metric. A person decides those.

Troubleshooting

• The message says GA4 isn't readable. Connect Google for the client, or give Nexus the GA4 property id.
• The message says no page falls below the site's average. Name a page and Nexus writes ideas for it anyway.
• The test needs too many days. The page has too little traffic for a small lift. Make a bolder change, or test a busier page.

Prompts

• "What should we A/B test on the site?"
• "CRO ideas for the pricing page."
• "Did the CRO test work?"

Machine twins: /help/cro-experiments.json · /help/cro-experiments.md · /help.json · /llms.txt

Reviewed 2026-10-15. In Slack, ask Nexus how do I … and it answers from this guide, with where your company stands.