What is Conversion Rate?

In internet marketing, conversion rate is the ratio of visitors who convert casual content views or website visits into desired actions based on subtle or direct requests from marketers, advertisers, and content creators.

The desired action can take many forms, varying from site to site. Examples include sales of products, membership registrations, newsletter subscriptions, software downloads, or just about any activity beyond simple page browsing.
A high conversion rate depends on several factors, all of which must be satisfactory to yield the desired results -- the interest level of the visitor, the attractiveness of the offer, and the ease of the process.