There are lots of “curiosity clicks” in the online world, and customer conversion occurs when website visitors move a step beyond surfing and take some action. Conversion is a marketing term for the action of a website visitor doing what the marketer intended.Conversion could be a website visitor buying a product online, filling out a form requesting more information, or joining an email newsletter list. Conversion is not just making a sale or gaining a new bona fide customer. It can be measured and defined however the marketing strategists desire.