For us, it was trade shows. We did the math: what would we pay per person to have them take a look at our software, and how many people did we think we'd get to

For us, it was trade shows. We did the math: what would we pay per person to have them take a look at our software, and how many people did we think we'd get to come by our booth at a show? I realize this can vary by industry though, in ours a standard booth is roughly $1000 which is far more affordable than most. We learned a ton and made contact with our first customers who ended up being vital in helping us refine our functionality.