Congrats on developing a SaaS with revenue . . . keep bootstrapping . . . you don't need investment.
Polish up your app and code . . . there are some rendering issues on initial load and validation on the login form. Test, improve, polish provide the best UX you can to keep existing customers.
Start a blog with articles on how realtors can use social media, publish often and collect emails/build a list, email that list valuable information and details on PropertyWizard.
Invest some of your revenue in contacting realtors, test out some ideas and see what your ROI is. Try calling realtors in person make a goal of 1, 5 or 10 per day, approach an office with 50 realtors and offer them a group package, test mailing out 100 postcards, track the realtor/office names/provide a unique URL and track signups. Find out what's working to generate signups and focus your efforts there.
Add a signup process on the site (checkout stripe), test three subscription levels, offer a annual discount sign up for 12 months (price of 10). Add an Office package up to XX realtors, email us for custom plans/more realtors. I think focusing on real estate offices with multiple agents might be a good way to grow your subscribers.
Add a favicon, minor but I always notice when they are missing from a site.
Don't sell a piece of your pie at this point, keep growing it.
Good luck, update us on how it's going.