The conversion rate is simple to calculate: number of conversions divided by number of visitors, times 100. With 1,000 visitors and 20 enquiries the rate is 2 percent. What counts as «good» depends heavily on industry and goal: for online shops 1 to 3 percent is common, while local service pages with a clear contact form can reach 5 percent or more.
Crucially, a conversion doesn't always have to be a sale. For a trade business the most important conversion is often a quote request or a phone call, for a restaurant a reservation, for a coach a booked first session. A distinction is made between macro conversions (the main goal, e.g. a purchase) and micro conversions (smaller steps toward it, e.g. viewing the pricing page).
Conversion rate optimization (CRO) tries to get more actions out of the same visitors – without more ad budget. Typical levers are a clear call-to-action, trust signals such as reviews and references, short loading times, simple forms and good mobile usability. Testing is often done with A/B tests, where two variants of a page run against each other.
The benefit is directly noticeable: if the conversion rate rises from 2 to 3 percent, you win 50 percent more enquiries at the same traffic. A CRO project for an SME in Switzerland costs roughly CHF 2,000 to 10,000, depending on scope and testing effort (without guarantee).