I’m not saying there isn’t a place for formal writing. Clearly, there is. But if you read a lot of business blogs online you’ll find that the tone is generally less stuffy and formal. It may still be professional, but the “stuffy” marketing schlock is all gone.
Online, people read for interest as much as anything else. And if you aren’t keeping their interest they’re going to leave you.
Keep your sentences short. Even punchy.
Your paragraphs too.
This causes people to read faster as they can scan your lines rather than feel like they are reading a chapter of Moby Dick.
Use humor. Make your content interesting and unique. But informative.
If you can do these things with your online content then you can build and audience and keep it. They will return and return to read what you have to say and send their friends by too. Develop a relationship with your readers and they’ll become customers. Drop the formalities, Madam.