3D animations give product advertisements a different appeal that is difficult to replicate otherwise.
CG designed advertisements can be very important to selling products or making an impact on the viewers. Photo realistic models are hard to distinguish from real world objects and thanks to the ability to use virtual cameras you can show different aspects of your products that simply aren't possible with real world cameras
Depending on the project CG animations can be significantly cheaper and easier to create versus a live recording since their isn't a need for actors, lights or a location to shoot. Production can be done anytime of day or night and from anywhere in the world.