Businesses should update or refresh their existing lead magnets when they are no longer generating new leads or when their target audience's interests or needs have changed. This is important to keep the content relevant and engaging for potential customers. For example, if a business offers a free ebook on social media marketing but the information is outdated or no longer helpful, it may be time to update it with the latest strategies and trends. Or if a company has been using the same template for their email opt-in for a while and it's not resulting in many sign-ups, they may need to refresh it with a more visually appealing design or enticing offer. By regularly updating lead magnets, businesses can stay competitive, attract new leads, and retain the interest of their target audience.