Many professional services firms struggle when selling and marketing "commodity" services -- work that they do that is virtually identical to that of their competitors. This means that clients have trouble choosing a service provider.
But consider what clients really value -- if they are buying a service that they are counting on to support their business, or particularly to manage risk, they want to have a firm that they can trust. One way to develop that trust is through 'how-to-work-with' content -- discuss how a client can get good results from a firm like yours.
This is helpful, useful content that also helps a firm stand out as being trustworthy.