You could try advertising more, for example, by putting up signs around the neighborhood, posting about it on social media, or having people you know spread the word. You could also try doing it in a different neighborhood that might have friendlier people, or do it in a time and place where there's likely to be a lot of people walking around the area (e.g., near a church before the end of a mass).
Sell plasma. After passing an initial screening, you can usually sell your plasma for anywhere from $25 to $50 per donation. To qualify, you’ll have to stand in a long line or show up early, be willing to fill out a very personal questionnaire, and endure a painful needle prick or two. Still, selling plasma is a great way to raise money fast – if you can stand the hassle.
Websites like Care.com connect parents with babysitters. The company does all the background checking and other due diligence to put parents' minds at ease. Of course, you can appeal directly to people in your personal network, but if you're looking to generate recurring revenue sign up with a site marketing to parents looking for child care services.