Sorry, reselling? How does this work, exactly? Would you find an upstream CA that is trusted, implement automation around their API, and sell certs? Why would

Sorry, reselling? How does this work, exactly? Would you find an upstream CA that is trusted, implement automation around their API, and sell certs? Why would I pay you instead of just using the upstream vendor? Why would I go to the trouble of dealing with you instead of a conventional provider like GoDaddy or Verisign? What about Let's Encrypt?