Here is what we did to prove some demand for <a href="https://weighttracker.co" rel="nofollow">https://weighttracker.co</a>. We had a minimum product (weigh in via email) and a simple landing page. We bought ads and AB tested the landing page. We learned we could get free trial signups for a reasonable price and got some ideas about headlines.<p>After solving some issues with the signup process, retention, etc. we've moved forward with mobile apps and are getting more traction and refining processes there. Progress is slow, but steady towards a working business.<p>If I were to do it all over again, I'd have a landing page with a sign up form and I wouldn't build the product until there were at least 100 people on the list. With a free trial or sign up form, you can probably AdWords or Facebook ads 100 people on your list for less than $1,000. Probably $100-500 if you don't overbid.<p>This also proves whether or not you can even remotely acquire users/trials for a reasonable amount of money. If you can't, you are going to have a lot of trouble scaling the business and it might not be a viable venture. $500 to learn that is a lot cheaper than dropping 100+ hours on a MVP.