Once you add in a proper confidence interval, 17 responses on a yes/no question is enough to make decisions like this - as long as you know in advance what your target numbers are. The downside of the small sample is that your margin is going to be extremely large, of course.

Using Clopper-Pearson at95% confidence tells us that between 23.3% and 70.8% would answer yes to this question. I do agree that is probably still too broad to decide to kill a business, but if you know you wanted a 60%+ (for example) positive response from this audience to hen that sample is enough to cause some serious worry.