Marketing and sales can be learned. Seriously. As long as you are able to validate that people have this problem and solve it in a way that makes sense the rest can be googled. If it kicks off, you can hire people with expertise to help.

Along the way for sales you'll have to learn how to put yourself out there, which can be challenging (it was for me). But its like speaking in front of people. If you do it enough times you learn to get by.

If your a founder, regardless of whether you the "tech person" or not, you'll probably have to learn all of this anyway.

Id second the "dont do it alone" part if its a full-time startup. Its tough going and having someone to share the burden in incredibly helpful.

If you solve a problem well, and it is a problem worth money to people - you can throw out some links on a forum or buy $100 in adwords and get a user or two.

A good advertising or marketing guy will help you go from 100 users to 1000 users, but you shouldn't need them in most cases to get a few users and start the path. Adwords isn't rocket science.

Now obviously there are exceptions, say if you are trying to create a 2 sided marketplace it's not so easy to just slow roll your product... but I think that is a fairly low % of total products.

I don't agree. Unless you literally don't want to learn it or don't enjoy it, there are lots of business/marketting resources for technical founders.

Lots of business people don't really know what they are doing, either, and more experienced people are often willing to help!

This is such a weird attitude to have when actively trying to start a startup. Both the over confidence in your technical ability to deliver something people actually want and the self-defeated attitude.