Adam Nelson brings an operator background from Twitter and Dropbox, where he led revenue partnerships, plus experience at two different VC firm types (Social Capital and FirstMark), giving him a distinctive perspective on how SaaS businesses scale and how founders should choose investors. He focuses on fintech, proptech, and vertical software at FirstMark, particularly companies that blend payments infrastructure with workflow software, and has developed a Negative CAC framework arguing that software-first fintech companies can acquire financial customers at zero marginal cost through their SaaS usage.