If you're going to have something in your marketing repertoire, use it.
How many companies have blogs attached to their corporate websites?
How many are inactive? Abandoned?
If it shows up, it either has a positive effect or it has a negative effect. Rarely do things have no effect.
How many of these neglected "blogs" are the result of a "social media guru" waving his hands emphatically and convincing their clients that blogging was easy and would result in massive new traffic and business?
Worse, how many of these stagnant blogs are the result of a senior executive looking around at the changing world and deciding that he needed to follow what everyone else was doing?