I had an interesting discussion today with an attorney about "why market?" And we agreed that most firms view 'marketing' as the path to increasing their client count (quantity). In my opinion that goal...increasing the number of clients, is a 'sales' objective. But the path to greater earnings is not isolated to increasing sales. that's where marketing comes in.
In the case of the firm of the attorney I was talking with, they are pretty much "at capacity"...so they definitely do not need to add clients on top of their existing load. But like so many firms, they would be well rewarded if they could increase the quality of the clients they serve. Now that's something marketing can sink its teeth into!
So when you're thinking about quantity, think sales; when you think about quality, think marketing.