Marketing comes later.
Marketing comes later.
I tend to interview 30-50 people initially to find a gap in the market. If I'm into something (strong PMF), a good percentage of those people I interviewed will be future buyers.
I typically have cascading meetings for the following steps:
1 - is this 10X better than what currently exists
2 - does our prototype look 10X better
3 - does our v1 solve the gap we found
4 - what features do we need to build in order to get you to pay for it
5 - what features do we need to get you to refer us to 3 friends
A meeting for each of those goals typically leads to customers (again, if I've found PMF).
If you can't find your target market, you might want to consider a different demographic that you understand better. Most successful startup founders started a business specifically to solve the problems they dealt with at their last job. They understand their product market fit because they ARE their target market.
First step is guessing who your customers might be.
But sure, I'm working on things for parents/students, home buyers, and DIY heat pump installers.
* Parents/students hang out at schools and are probably a good referral/recommendation crowd
* Home buyers are looking for mortgage comparisons on Google (but that's probably a terrible strategy, since this is a highly lucrative segment to market to, so you should expect high customer acquisition costs)
* DIY heat pump installers will probably look at ads on /r/DIYHeatPumps
But it seems to me that there are many projects out there like mine. You start building something because it scratches an itch you have. You think it would be fun to build. You keep adding features and fine tuning the code because you want to see something work better and/or faster than anything else.
Then one day you look at it and say: "I wonder if other people will think this thing is as useful as I do (and be willing to pay something for it)?"
It might still be a work in progress, but it does a number of very useful things, so you now have to put on your marketing hat or team up with someone who is good at that.
Marketing comes first. Sales second. Product third.