Commercials and websites essentially serve the same purpose: they exist to captivate an audience and retain their interest long enough to inform them about their product or brand.
If executed successfully, they will both garner more interest and goodwill toward the product that ultimately leads to heightened brand awareness and the generating of revenue.
While both require artistic talent and creativity to be successful, one would be remiss if we were to approach these mediums purely as an artist. Success is achieved when there is communication to a specific demographic that is influenced to proactively act in favor of the product. Simply fulfilling an artistic indulgence does not suffice.
While evaluating art is wholly subjective and shrouded in enigma, there are certain yardsticks that can be used to measure a successful commercial or website.