For those who keep track of the real estate market, buying, selling, and renting property could be a viable financial investment. Not only will you realize capital gains if you invest in the right property, there is also the possibility of earning rental income. If you had purchased your property relatively early in your career, at retirement you may have paid off the property’s mortgage and so whatever rental income accrues is basically your profit (minus, of course, maintenance).
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).