Let me start from the commonalities: You are building something that solves a user problem and creates customer value that also generates business value in the process.
The line between enterprise and SMB is fluid, though in the case of companies like Faire (and I also observed this at Airbnb and Travelnuts to some degree), SMBs often act more like consumers.
Two key differences are:
- Where you get your insights: The research process tends to be more consumer-esque for SMBs, where you rely on user research and experimentation more than on sales teams or account management teams for insights. Often enterprise products are more likely to have a sales driven roadmap since the sale is often contingent on having/ promising specific features.
- How you release product and measure success: The larger and more fragmented your user base (more likely for SMBs), the easier it is to launch experiments and A/B tests that give you a statistically significant result. For enterprise, it is harder to exclude large and important customers from improved experiences at random, thus you are more likely to work with betas and pilots, which will inevitably have less rigorous results.
There are many more but these are the two that most stand out for me.