Ask HN: How to validate B2C software ideas?

Find customers before building is a popular tactic in B2B SaaS where you conduct user interviews before even building the MVP. I think that works well because business people are used to getting cold calls/meetings. But what about B2C ideas? How do you conduct interviews? Are non-business people used to getting sales call? Or is there a better way for a software that costs say $30/yr?