There is no right answer to this question because it will be different for every company. To be able to develop a successful strategy, you have to get a good picture of where you're at now, what's been stopping you from growing bigger / faster and how do you want the company to grow. Once you have clarity over these points, you can start building a strategy and test the different scenarios.

Here are some of the questions you may want to get answers to before spending any money on sales people, ads, etc:

1. What is your bigger vision? What does it look like when you've made the company the way you want it to be?
2. What does success look like for you? How will you know you have achieved what you wanted to?
3. What problems do you solve? Who has these problems? How much is it worth for these people to get the problems solved? How big does it make the market? What are the different segments? Do your services cover all the different segments of these markets?
4. What are your current strengths and weaknesses? Where do you make most of your money? What are your least profitable activities? Where do you spend most of your money?
5. What has been stopping you from growing bigger / faster? What have been your most successful channel / initiative for growth? What have you already tried that worked / didn't work?
6. What are the opportunities in the changing world for your business? These changes can be social, technological, economic, environmental, political, legal or ethical.
7. How much money do you have to invest and what return do you expect? How much time can you give yourself to test different solutions?
8. What do your clients think of you? Why do they use your services versus competitors? How do your clients find you?
9. Who are your competitors? What makes them more / less successful? Why do their clients use them versus you? How do their clients find them?
10. What will you personally gain from having a more successful company? What's in it for you? How does it make your life better / happier?

I have helped several companies through this process. What's important to remember is that the answers will be different for every business depending on the industry, the environment you're in, your reality, etc.

Do you want guidance to develop a growth plan for your business?