[Barrin92]

The defining feature of tech is marginal cost of production close to zero at scale . Meaning, as you grow your business you increasingly automate away human labour. That's why Instagram was worth billions with 13 employees.

You're not a technology company just because you rely on software. Walmart makes software too, much more of it than airbnb actually. You're a technology company if you automate away human labour. This doesn't really seem to be the case for most of these 'marketplace' companies which is reflected in their margins. They just have to keep adding more labour as they expand.