Guy Kawasaki has an interesting article “The Art of Evangelism”.
In some ways, it sounds a lot like my job, in others, it doesn't. I am pretty pragmatic overall.
I do speak the good words about the business processes and technologies with which I work; my time is split almost equally with partners for whom our technology is, and isn't relevant. Many of the solutions I propose could be done with other technologies, but in many cases can be done more easily with our ecosystem.