If you are not making sign-up mandatory, you would not be able to validate the pain point of the problem. People normally would give you their email address(or

If you are not making sign-up mandatory, you would not be able to validate the pain point of the problem. People normally would give you their email address(or even pay through their credit card) if you are solving burning problem for them. For self funded start-ups, this may not work. However, this technique discussed in the article may work for consumer start-ups where you think of making money later and your present problem is to get millions of users.I assume you have sufficient runway(could be in the form of venture funding) to follow this approach.