What are ways to break down functional silos within marketing (e.g., consumer insights, sales, product management, etc.) and between marketing and other functions of the organization?

What are ways to break down functional silos within marketing (e.g., consumer insights, sales, product management, etc.) and between marketing and other functions of the organization?                                                                                                                                                                                          

What are the potential benefits to marketing and to the wider organization? How should marketing be organized for start-ups?