Look at what other successful promoters are doing and see if you can do something similar. You could create a generic release PR and tailor it for each spot where you are going to promote it, then submit away
When you have to spend money on something you don't understand, where do you go? To that one mechanic, hiking gear store, tax advisor who has always been honest with you. People will drive across town to specifically visit their trusted business. They'll sign blank cheques to them.
This is how I behaved towards the small businesses I worked for, and it's how I behave towards my readership. I was always rewarded for it in the long run.
This also applies to cold marketing. I have picked many products because I found their blog and it wasn't a shallow content marketing attempt. This especially applies to experts like lawyers.
Sometimes the right investors can open doors, but going the VC route is so awful that I don't recommend it to anyone. If you're talented enough to get venture funding, you can probably get $200+k/year, easy job at a big company that lets you go home at 5pm.
It worked for the My Pillow guy.
Maybe you could try google advert -> free consult offer e.g. 4 hours free related to product area -> offer product and/or paid consulting
Or something like this.
Could be a white paper that is actually useful instead.
Basically shift towards marketing away from pure selling