Marketing can be a difficult investment to see a clear return on, law firms are often accustomed to clear returns, this client is billed this much money for this much time, simple. Therefore, a long-term strategic approach to a marketing strategy could, at times, feel like throwing money into a blender and not getting any useful return. 

Sue Bramall's timely post-christmas comparison to a diet fits this well.  A diet can feel like it is going nowhere, until that one day you glance in the mirror and like what you see. As with marketing, eventually, if things are done correctly, a SMART strategy, tactics and timeframe applied, you will begin to like what you see. 

However, like a diet you cannot simply stop there. Keep it up and progress, this way you will continue to like what you see; go back to your old ways and see everything return to how it was.