I would certainly hope so, giving that a survey by Special Events magazine found that half of the respondents were already writing one. And I have to admit that some of my favorites are blogs by special events people, especially when they post photos of some of the things they are doing (or wish they could be doing).
The article includes some interesting success stories, with "success" meaning blogging is bringing in new business.
While I can't say this blog has made me a millionaire (or financial gain of any sort, for that matter), since I started it back in 2003(!) I've met more interesting people, made connections I can't imagine having made any other way, and gotten some great ideas for stories (and feedback on stories we already ran). While I don't think blogging is all that cutting-edge anymore, the only reason I can think of not to be writing one is that you just aren't interested in this particular way of communicating with your clients, colleagues, and others who just might mean potential business.