I have a new website that I'll be launching soon. It will be a niche social media site. While I'm promoting the site through various methods, I'd like first-time visitors to the site to get the appearance that it is already active. Few people will want to join the site if it appears dead / inactive. So I'd like to get a team of 15-20 people to post actively on the site. This will give an appearance that the site is buzzing & active, and will encourage new visitors to register.
Does anyone have any recommendations about how to get these users? I believe there's a site that allows you to get people to test your site (something like UserSays.com? Can't remember the exact name), but that service's main focus is to provide feedback about the user interface, so not really relevant in this case. I suppose an alternative is to recruit people individually through a freelance site.