Recently I was chatting with Reilly Chase about finding customers by monitoring online communities. He suggested that it’s a good idea to monitor Upwork, a job board for freelancers.
A few hours later I had a prototype ready, and Syften was already processing job posts.
You can read about how Reilly uses Upwork to find customers for his SaaS here: https://syften.com/blog/post/upwork/