Tone of voice is the personality of a brand, reflected in its words. Just as you might recognise the sound of your favourite band, or the style of your favourite painter, so you can recognise some brands by the way they write or speak.
Tone of voice helps your brand communicate on three levels, each supporting the next (see diagram).
The first, and simplest, is consistency. When all your stuff is written in the same tone, people can recognise your brand’s ‘voice’ whenever it ‘speaks’. It’s the verbal equivalent of visual identity.
The second level is character. Once your tone is consistent, you can use it to express a personality that people might like.
Maybe not everyone will like that personality. But that’s part of the process of knowing which people you’re selling to, and being willing to forget the rest.
The third and final level is value. A consistent, likeable tone can help to build trust in a brand, by putting positive product experiences into words. If you reach this peak, people will listen whenever your brand speaks, because they expect to hear about something good.
There’s loads more on translating brand character into a written tone of voice in chapter 15 of Copywriting Made Simple.