Content marketing from professional services firms is, I would argue, considerably better than that of other B2B brands.  Why?  Because it broadly follows the 'teach, don't sell' mantra. 

We are bombarded daily by hundreds, if not thousands, of buy messages.  And for the most part they are ignored.  The overt sell is a complete turn off. 

However, by being generous with our knowledge and sharing genuine insights the sell is more subtle and covert.

By all means brand that content - that is expected and adds a degree of credibility.  But take care with a call to action.  'Contact firm X for advice' is in many instances to strong;  'Contact Joe Bloggs for more information' is a little more subtle and suggests that there is more insights to be had.