That's what makes marketing campaigns that use the new tools of social media possible.
Even if, as a New World filmmaker or marketing professional, you have the most brilliant viral video idea ever - you won't get the funding you'll need to execute (much less, get the money you'll need for your next job) unless you can show just how successful your campaign has been.
As Steve Goldner wrote in a businessgrow.com blogpost: "You have to show results in a manner that is relevant to the stakeholders’ perspective. This means being able to measure awareness, consideration, loyalty, and advocacy. Notice I did not mention sales. Social media is generally a weak vehicle for direct sales, BUT awareness, consideration, loyalty and advocacy ALL contribute to sales."