Marketers define conversion as mostly the point at which the recipient of a marketing message performs the desired action i.e. responds positively to your call-to-action. Conversion can take different forms. For example, getting someone to open an email is a conversion, having them click on a call-to-action button inside that email is yet another conversion. Going to the landing page and filling out a form to download an eBook is conversion. And ultimately, making a purchase i.e. buying your product or service online or subscribing to a paid plan is a conversion.