Qu'est-ce que Conversion Rate ?

Conversion rate is calculated as (conversions ÷ total visitors) × 100. A website that receives 10,000 monthly visitors and generates 200 purchases has a 2% conversion rate. The 'conversion' event varies by context: for an e-commerce site it's a purchase; for a SaaS product it might be a free trial signup; for a professional services site it's a contact form submission or call booking. Each funnel stage has its own conversion rate — from ad click to landing page, landing page to lead, lead to sales call, sales call to close.

Conversion Rate Optimization (CRO) is the discipline of systematically improving these rates through evidence — user research, heatmaps, session recordings, A/B testing, and funnel analysis. Common CRO levers include improving headline clarity, reducing form friction, adding social proof (testimonials, reviews, trust badges), optimizing page load speed, clarifying calls to action, and aligning messaging with the specific intent of the traffic source. Small improvements compound dramatically: increasing conversion rate from 1% to 2% doubles revenue without spending an extra dollar on traffic.

CRO is distinct from increasing traffic. Many businesses reflexively invest in more ads or more content when the real constraint is that existing traffic isn't converting. A conversion audit often reveals fundamental messaging or UX problems that no amount of additional traffic can overcome.

Conversion rate is the multiplier on everything else you do in marketing. The business that converts at 4% gets twice the revenue from the same ad spend as the competitor converting at 2%. Most companies have significant, unrealized conversion opportunities hiding in plain sight — unclear value propositions, confusing checkout flows, landing pages misaligned with ad intent, or trust signals that are absent when they matter most. A CRO or marketing expert can audit your funnel, identify the highest-impact fixes, and design and interpret the A/B tests that prove what actually works at your scale.