Sure, talk his/her boss out of his/her having a job. (I think both are “her” but not sure.)
In this case our op is confident of this much: the marketing folks usually handle social media wrong and her approach (“informal, fast, completely without hype, and offering honestly valuable information or content, whatever that is in context”) is better. She does not doubt her ability to use the media in a way superior to what she sees as the way she perceives the marketing specialists do; she just needs the sales pitch to get her boss to have confidence that her method is worth its investment. (And FWIW she may be right, radical concept that it is, actual useful information quickly obtained may actually make for customers who return and who recommend you to others even more than smooth hype. Who’d have thunk it? … But how to prove it?)
Now collaborating with the marketing and CS people to get some data that could demonstrate that those who have used the page are more satisfied as customers, more likely to recommend the company, less likely to need to call for help (because they got the information from the page), etc. … that makes sense (to this non-business person).