I think a lot of SaaS companies end up failing fast when they focus on the enterprise. The sales cycle is longer, and having a massive client can end up putting their individual needs over features that would make the product more attractive to the market as a whole.

SaaS makes the most money when users can self-service in large numbers at relatively low transaction costs, which typically means SMB should be your first market. The enterprise channel is where you go only once you have a mature product and a healthy revenue base to do the enterprise payola scheme with consulting companies.