When I was a young actor living in San Francisco, CA. I took my first on-camera 1:1 lesson for commercial acting with Ed Hooks. I remember him sharing with me that you need to choose one person you are talking to and the camera IS that person. If you try to convince everyone, you will convince no one. I also remember him giving me a script for a BBQ sauce commercial and saying, “When you refer to your husband in this reading, pretend you are talking about your small child.” Ah, the subtle and condescending, oh isn’t he cute out there at the grill gender role stereotype. Ya gotta love marketing.
The point is, that not only for commercial acting, but for any direct address to the camera or a theater full of people is to know your audiences, know who you are talking to, and be clear about what you want them to do.