- 37 Signals
(because you're going to object that they're the only ones, here are some more)
- Fog Creek
- Amazon EC2
- Visual Website Optimizer
To my knowledge, none of them have travelling salespeople. Acquisition cost is likely higher than with consumers, but likely nothing like the costs associated with an outside sales force (or their prices would have to be higher).
Everyone says 37 Signals is an exception, but I think that's just lazy thinking. There are lots of enterprise businesses that don't do expensive outside sales.
There are different risks selling to businesses, but B2B businesses don't need massive scale to be able to pay their rent. So if you're bootstrapping, B2B is likely to have a higher probability of non-failure.
I find that other parts of the enterprise market are surprisingly harder to reach. In enterprise companies information sharing is often discouraged, many folks working in the enterprise are hesitant to mention what products they use let alone promoting (or criticizing) them. Successful SaaS companies addressing the enterprise seem to either gain traction elsewhere and then try to penetrate enterprise or spend tons of money for marketing and sales.
In the end why leave massive wads of money on the table, do both.