Thank you, this is a crucial point.

On existing solutions (GLG / building an audience): This is the practical fork in the road you're highlighting.

Outsource (GLG, panel vendors): Effective but often cost-prohibitive for a bootstrapping founder validating a risky idea. It's a capital-intensive solution to an information problem.

In-house (Build an audience/marketing): This is the "correct" long-term answer. But here's the rub: Building an audience is a product in itself, requiring months/years of consistent effort before you can use it to validate your current idea. The founder's dilemma is they need feedback now to decide if they should spend 2 years building the audience.