If you want to work with large companies, being SOC certified makes it easier. Part of that is ensuring your vendors are also compliant with good standards and that's best done with SOC reports.
https://news.ycombinator.com/item?id=41304228
This SSO cost post is also interesting:
We did not get certified because we wanted it, we did because the enterprise scale customers forced us to. Due to their internal bureaucracy.