Answer:
Use Seperation Of Light
Step-by-step explanation:
The reason to match the color of the backdrop with what should be the background color in the final image (on a website in this case) is obviously that you "get it right in camera" or at least very close to it. It saves you the whole process of cutting out the subject from the background. Maybe you missed the intention of the suggestion, but the point of using the black background is that it will not be cut out anyways.