Brand voice is the tone and personality of your written words, which can jump off the page and engage your readers in subtle, almost undetectable ways. The strength of your brand voice in large part depends upon the appropriateness of its personality, and your consistency in implementing it across all your content channels.
Consider your brand a living thing. It has a unique personality and characteristics you can't fully control. Over time, you can watch it grow, nurture it, and guide it to fit its environment perfectly. But sometimes your brand begins to deviate from the factors that support it, and your strategies start to suffer as a result.