You can definitely use user-based platforms like Facebook, Twitter, etc to boost traffic. Your question might be general why my answer's this way. But personally, I've used Facebook to generate engagement on my niche given that the people I target have genuine interest on it as well.
With Facebook , you can set up a page with a tab that links to your minisite. Or simply use Facebook as a separate site on top of yours.
And I've not yet even mentioned the Ads Manager provided with your FB account. If you really want to get more traffic, that's an option and there are plenty of folks who share their knowledge using it. Make no mistake about the simplicity of the social site's interface. Details matter when it comes to setting up ads - like most advertising platforms, you'd have to set up your parameters which I think you can also apply on your posts and pages, not only on ad campaigns.
If you're looking for a reputable platform, well I've learned that they have a high intolerance to folks not following their guidelines and I believe they've updated their NewsFeed algorithms again so that it's mostly user-based / user-generated. I'm not quite sure on details of that last bit so good Luck on your findings.