Cookies are small pieces of data that are stored on a user's computer by a website and contain information about the user's visit to the website. They are commonly used in digital marketing to track website activity and to personalize the user's experience. However, it is possible to do digital marketing without using cookies. Here are a few ways that digital marketing can be done without relying on cookies:

1. Use browser fingerprinting: This technique involves collecting information about the user's browser and device, such as the type of browser, the version, and the operating system, and using this information to track the user's activity on the website.

2. Use server logs: Websites can track user activity by analyzing the server logs, which contain information about the user's IP address, the pages they visit, and the time they spend on the website.

3. Use alternative tracking technologies: There are several alternative tracking technologies that can be used to track user activity, including web beacons, pixel tags, and local storage.

4. Use first-party data: Brands can use data that they have collected themselves, such as email lists and customer databases, to personalize the user's experience and deliver targeted marketing messages.

5. Use offline marketing techniques: Digital marketing is not the only way to reach and engage with customers. Brands can also use offline marketing techniques, such as print advertising, direct mail, and event marketing, to reach their target audience.