If you have no idea where potential consumers of your product might be, you shouldn't even start building something to target them.

Not sure why you are getting down voted. It's true. If you are trying to get people to use your product, your best bet is to start with the people you validated against. Have them help you in this regard. If you don't have those people, you are effectively doing things backwards.

So don't make a product without knowing the potential user base first?

Otherwise, you are making something for no one.

You should. Just don't expect to make money off it.

Correct.

To the downvoter(s): this comment seems like a rude quip for its own sake but if you think about the reasoning behind it I believe you'll somewhat agree.

It's not intended as being rude, I was going for succinct

It's sometimes hard to tell! I had to read it twice, but then I thought, "well that's not rude, that's quite profound". I guess whoever downvoted didn't read it the second time. It was a good comment, I voted it up.