Personal, happy, trustworthy, hip/cool, immersive/experiential, consistent, motivating, networking, funny/weird, selfless (customer-centric) - these are the emotions successful companies have employed to reach the pinnacle in their markets. Think Apple, Target, Amazon.com, Coca-Cola, Nike, Southwest Airlines, etc.
To make these emotions ring true, you need people that can represent the brand well and evoke the emotions you are trying to convey. Bill is a comedic and engaging personality that is able to marry humor with trust - a powerful way to deliver a message.
It's your brand. In a word, it's everything. It speaks to your company's story, it's reputation, quality and character. It should exude confidence or understanding, it answers a question without the question being asked. And once you've gone down a path with a face to your campaign, you should be happy with the one you've selected.
That's where Bill comes in. When you are looking to put forth a long-term branding initiative, you need look no further.