You can advertise through social media.Many people use Facebook,Twitter,Google+, Reddit ...such sites...so you can create a profile and attract members through that.Marketing/Promoting is very important for any business...it gives the business a recognition.Online marketing is heeding its way in a faster pace when compared to traditional marketing.I think this is due to the increase usage of internet among people.Also this type of marketing is simple,cost effective, reach a larger crowd instantly and even the results can be traced back using tools.Internet marketing involves E-mail marketing,SEO,article/blog submission,rewards or discounts through their website,online advertisements etc.There are providers like Thewebpole.com where they provide this email marketing service,SEO techniques to improve the business.