If your content appeared without your logo, would your audience know if the content comes from your brand?
Finding and staying consistent with your brand voice is an essential component of branding, especially for e-commerce businesses that have little to no form of face-to-face interaction with their customers.
The brand voice has one purpose: to outline your brand through language.
How does this increase sales?
Unique brand voice causes higher brand recognition, which increases customer trust. Customer trust has a positive impact on buying behavior and customer satisfaction.
Find existing content that reflects your brand
Inspect your channels thoroughly and choose 3-4 pieces of content that reflect your brand the best. Be meticulous. Ask: "could this piece of content have come from our competitors?". If the answer is yes, remove it from the list.
Acknowledge what you are, and what you aren't
Once you have your samples, define 3 core brand traits. In addition to analysing the samples, I like to use a question by Paul Boag:
"If this brand was a famous person, who would it be?"
Look at the traits of the celebrity to garner inspiration for your own brand voice. Once you found 3 characteristics, think about how you can communicate them. Define do's and don'ts for each trait, and create sub-traits when you feel that you have to. For example, you may want to mediate confidence by making fun of your brand's own missteps. In that case, the core trait would be "confidence", the sub-trait would be "self distance".