How to Validate Demand for Your Product
I didn't write my book on how to break into consulting until I validated demand.  Here were my step:1.  Write up a table of contents2.  Throw up a quick landing page on unbounce.  This was the page I used http://unbouncepages.com/become-a-freelance-software-consult... (but I did a 1month trial of Unbounce premium so I could cname it to codeforcash.zackburt.com)3.  Bought traffic on Reddit ads (/r/programming) and Facebook (programmers in USA).  BTW, two young kids (a college student and a recent graduate) commented on my Facebook ad to bash me.  The ad performed better after their comments.I got email signups from Reddit at $4.50 net Cost Per Lead and from Facebook at $6.50 net Cost Per Lead.  I spent a total of $100 buying traffic before I sat down to write the book.  Although there was no way that 100% of the emails would convert to sales, (ultimately, about 35%+ of them did so far), it was clear to me that there was a potentially scaleable marketing channel (once I optimized the ads to drive down cost and improved conversion rate on email -> sale).  That, and people on HN constantly ask how to break into consulting, so I also intuitively believed in the market.But these days I am reluctant to dive into anything unless I know there is a repeatable sales process. I qualify potential startups as employers or clients based on this belief – I don't want to waste my time and I don't want them to waste theirs.  I've been burned WAY too many times by startups with products or services that haven't been proven to have economic demand.  Let people vote with their wallet not their mouth.