On thing that is really important here is to look at the supply side of your marketplace vs. the demand side of your marketplace.
For example, pre-launch, you would typically expect a jobs marketplace to have a supply of job opportunities before marketing to job applicants. The approach one jobs marketplace took was to attract a lot of workers to their marketplace first by scraping jobs online. With an inventory of job opportunities we could attract job seekers. This approach allowed them to scale across the United States and open up in 20 markets in a matter of months!
With job seekers they could launch our marketplace and then attract their own job opportunities which we could monetize.