Do you have anyone in your network that can test out your MVP, and actually use it in their company? What I found in the beginning, if the MVP you released is kind of crappy, which it should be, is that it's difficult to get people to make the time investment needed to test it out and give valuable feedback. When it's someone you already know they are more likely to actually commit the time.

Also, at this stage I don't think you should measure success by how many users you get but rather by how happy your users are. I think zapperdapper is spot on with saying you need to find one customer who loves your product. Once you have that customer try using her to find out how to reach similar customers. Which online communities do they belong to? Where do they get their industry news? Can she recommend your SaaS to other potential customers? Can you maybe attend industry events? What sales language does she respond to? In her own words how does she describe her problem and your solution?

Also, if you post a link here, maybe HN can help out?