I'm a licensed real estate agent and multifamily unit rental property investor in Georgia, as well as an internet entrepreneur. You're correct; you must hold a real estate license to collect a referral fee. However, this isn't the only way to monetize your website. You could select from a wide variety of monetization methods, such as CPM or CPC advertising, charge a flat fee per listing, or use the site as a lead generator for webinars, seminars or premium material. In short, there are many ways to create revenue streams from your site that go beyond simply collecting a referral fee. (Bear in mind also that referral fees on rentals work differently than referral fees on buy/sell arrangements). If you'd like to discuss these ideas in greater detail, I'd be happy to speak with you by phone. Thanks!