You can't think of buying traffic as an expensive proposition. All in all, organic "free" traffic is always more expensive in the long run. Properly targeted paid traffic is the best investment you'll make.

As for ways to get organic traffic, create demos on how people can use your software to solve their problems. Use a blog and youtube videos to demonstrate the capabilities of the software by solving a specific issue. Do not just make a demo of the software to show the features, it must show a solution.

Participate in social media and answer questions for the consumers. For affiliates, offer bonuses and special offers to join your program and nurture the affiliates. Find them by name and approach them personally to review the software and use it. You also should give it to the affiliates you want to promote your product, for free.

I'd be happy to help you over the phone with this when you are ready.