It’s simply possible to have too many clients and have clients that require way more time and effort than they are worth. If you have the time, energy, and manpower at your disposal then, by all means, take on new projects and grow your business. However, if you don’t have these limited resources (and they are limited!), don’t place an unneeded burden on yourself or your team to pull an excellent final product out of thin air. If you over-commit yourself then there is the risk of not spending the time and effort needed on existing work, making your current clients unhappy and potentially driving them away. It can be very tempting to obligate yourself to new projects that could be enjoyable or lucrative for you and your team, but if you know that you can’t handle the work at that moment, it can be better to say “no” then to risk your reputation and good name.