Absolutely.

I'm a "Reddit Marketer". I built a business and acquired all my initial customers from Reddit and Facebook Groups, without spending a dime on marketing.

We hit 6 figures in revenue our first year.

I wrote about this, and ultimately my post became the #35 Top Post of 2015 in r/Entrepreneur, a community of nearly 200,000 members (and drove even more clients to us): https://www.reddit.com/r/Entrepreneur/comments/3s5e7m/0_to_6_figures_in_1_year_lessons_learned/

I also wrote an article called "How to Market on Reddit (Without Getting Eaten Alive)": http://launchyourrevolution.com/market-reddit-without-getting-eaten-alive/

I've gotten several posts to the front page of Reddit (the #9 most popular site on the internet), including this one I did for The Askhole Podcast: https://www.reddit.com/r/funny/comments/40zrh9/give_a_man_a_fish/

I can provide verification that this was actually me, and screenshots of the post reaching the #10 spot on the front page of Reddit.

I am extremely comfortable marketing on Reddit, so let me know what type of business/service you're wanting to promote, and I can give you some advice on giving it the best chance of success.