We focus mostly on website and landing page design, with a strong background in conversion-driven design and CRO principles.
I'm more an expert on how to convert leads into clients, so take this with a grain of salt... I see digital marketing companies advertise on facebook all the time.
I know some of my marketing buddies also like to start out with Adwords to validate an idea. The thinking is that your best chance of getting leads when you are new is to catch them when they are searching for it and it is on their mind.