How do you think about the differences between "enterprise" product marketing and SMB or mid-market?

The main difference is around change management. When SMB and mid-market companies buy software, there isn't a huge change management aspect because of their size. "Enterprise," defined as more established companies like (P&G, etc.), would like to know how you will help them succeed with your software.  

So this means services, solution partnerships, and etc. The other two differences are pricing and packaging and multiple persona messaging. Enterprise like to buy with scale and with value, so the right pricing and packaging is important. The last is around multiple persona, I haven't been in a situation where the enterprise was just one main buyer and no other stakeholders, so its important to message to the buying committee.

The last advice I would give is define what enterprise means for your company. The definition should go beyond just company size, but including vertical, persona, and etc. The detailed definition will help you define your GTM strategy and messaging. Most growth companies fail at the above and most large companies rely too heavily on their size as a differentiator.