The HBR's The Freelance Economy Still Runs on Word of Mouth covers data from the MBO Partners State of Independence study showing word of mouth is the dominant way freelancers and other independent workers find work.
The chart below describing this data is from the HBR article.
What is interesting is it's not just this study. All of the studies we've done looking at this topic over the last few years shows word of mouth is not only the dominant source of work, but if anything is becoming even more important.
The chart below is from the Freelancers Union's How to Live a Freelance Life study. It also shows the importance of networks in finding work.
The results were also the same in a Career Advisory Board study of successful independent workers.
That study surveyed folks who had worked as independents for more than 8 years and had higher than average incomes. This group also reported word of mouth was their dominant source of jobs.
It's not surprising networks are important, but it is surprising how important.