Conversion rate
The conversion rate is the proportion of people who take the expected action (submit an inquiry, buy, sign) among all those who had the opportunity.
The formula
Conversion rate = (Conversions ÷ Total) × 100
A concrete example
Example
40 inquiries for 1,000 visitors: rate = (40 ÷ 1,000) × 100 = 4%.
Why it matters
The conversion rate acts as a multiplier on your whole acquisition: improving it mechanically lowers your cost per lead and per customer, without spending one more dollar on advertising.