While some promoters claim to have "safe and secure" methods, these often result in severe penalties. Permanent Account Ban
Provide a settings interface (e.g., in a CMS plugin or site config) to control the behavior:
Years ago, the standard AdSense loading method was . The browser would request the ad, stop rendering the rest of the page, wait for the ad server to respond, then continue. This was simple to implement but catastrophic for user experience.