Hi mogli, TL;DR - we use it to avoid inundating you with messages you're not interested in and to improve the product experience. We use a system from our parent company, Avast, to deliver dynamic content, such as the 'CCleaner Pro upgrade' message and the CCleaner Product Tips. When you see one of these messages, a cookie is left behind. This helps us to avoid sending you sales messages over and over again, and it also allows us to run A/B tests that help us to understand which messag