What is the mechanism of retargeting in digital marketing?

The correct answer highlights that retargeting in digital marketing specifically involves showing ads to users who have previously visited a website. This mechanism works by using cookies or tracking pixel technology to identify visitors and align advertisements with their previous interactions. When these users leave the site without completing a desired action, such as making a purchase, retargeting comes into play by displaying tailored ads on different platforms or websites they visit subsequently. This approach aims to remind potential customers of the brand, encouraging them to return and finalize their transactions, thus increasing conversion rates.

The other options do not align with the definition of retargeting. Displaying ads to new customers focuses on attracting individuals who haven't engaged with the brand before, which is a different strategy known as outreach or acquisition marketing. Sending direct mail to potential customers is a traditional marketing tactic that involves physical mail and doesn't utilize digital tracking or online behavior data. Lastly, distributing ads only on mobile devices narrows the scope of retargeting, as it typically encompasses users across various devices and platforms, not limited to just one. Therefore, the essence of retargeting is to reach back out to those who have shown prior interest, making option B the most accurate representation of the mechanism.