The reason my agency has longer than average tenure with clients is because we nurture new business. I say nurture because that is a key to having relationships built on trust. Nurturing new business takes more time, but it gives trust a chance to take root. Before the client even hires you they feel connected to you. They know you know their business and their problems and that you will help them overcome their challenges. I won't go into what we do but suffice it to say the proof of you being the best fit for a client happens by being not selling.
Imagine your agency working to its potential. Imagine clients seeking your counsel and appreciating your insight. This is what the right client brings to your agency. There are more "perfect" clients than you might believe. Too many times agencies don't nurture, they just sell to whomever is buying and they reap what they sow. We all know what happens when a client is not buying what we're selling. It's miserable for everyone involved. This is another reason we can avoid growth. You become convinced that there is only misery out there and why ask for more heartache? Choose wisely. Walk away from the obviously bad prospect. Don't believe you can fix them or train them to be good clients. Look for something better and you'll find it.
Growth will not keep you from being the size you want to be, it can empower you. I've always admired agencies that are willing to walk away from clients that aren't a good fit. It's only possible when they are in control of their business. The effect on one's bottom line must be manageable. Let's face it, if it's inevitable that a relationship is going to end, why not be in control of when it will end?
New business efforts should never be put on the back burner. They should always be a priority so that you remain firmly in control of what your agency is going to accomplish.