Do most startups have an unfair advantage?

Excited to be in the community. My co-founder and I are launching a marketplace this year (too early to share), and initial feedback to idea has been positive. However, I don't know how to answer the question "What's your unfair advantage?". Did any of these companies initially have an unfair advantage: Airbnb, Twitter, Facebook? Their business models are relatively simple, and do not appear to be technically difficult (I'm non-technical).

Can the group share how they answer the question for their startup? Or an example of a good answer they've heard?