If you're in an industry niche and solving a valuable problem, you can charge a lot more and afford to sell directly to your customers, potentially in person. Acquisition looks like it costs more, but if you're a one person show and it's your time, then that's a sacrifice you can make as you're trying to bootstrap your business.
Just a contrived example, if you're selling telemetry software to motorsports garages, you could have the margin and the value-add to go knock on workshop doors and sell if it's valuable enough to them.
I think there's still a lot of hard software problems to solve in grass roots industries, with customers that you can go visit in your city. I think we get stuck in the idea of selling software to the internet and software industries.