Something that I failed to realize when I started my marketing agency was just how much of my time would be dedicated to sales. Yuck! As an introvert with some mild social anxieties, the idea of calling hundreds of people that I have never met in my life to sell them a service is dreadful. Even now, 4 years later, I dread the task. It's still by far my least favorite part of owning my agency. The positive is that now I'm much better at those sales calls. That's because doing it made me more confident and helped me really nail my elevator pitch.
If you're a young entrepreneur who runs a service-based business I would recommend fitting cold calls into your outreach strategy. Just be repaired to hear "no" 1,000 times before you hear a "yes".