Timing: Use delayed pop ups that appear after the visitor has spent some time on the page or is about to leave. Relevance: Ensure the content of the pop up is relevant to the page the visitor is on. Design: Make pop ups visually appealing but easy to close. Avoid covering the entire screen. Frequency: Limit the frequency of pop ups to avoid overwhelming the visitor. Value: Provide clear value, such as a discount or exclusive content, to encourage engagement.