Become a certified wedding planner?

Hello all! I began my wedding planning business in the summer of '09, and I'm making my plans for 2010. I've been looking into various Wedding Planning Courses (LWPI, IWPP, etc.) and considering taking one, but I'm not sure if it's worth it. I of course did a lot of research before deciding to start planning weddings as a career, and I do have experience planning weddings for many of my friends and family- so I don't feel like I went into this blind. I'm sure that by taking a class I would learn things, but I feel I could learn them just as well from networking, reading, and experience. I know that being able to say that you're a "certified wedding planner" improves your reputation, but I'm curious to know how much it really matters to potential clients.
I guess what I'm really asking is- should all wedding planners take a course to become certified? Should I do it right away, in the beginning of my business, or can it wait until I have more disposable income to pay for it? Do you think brides care if we're certified? And finally, if you took a course, which one do you recommend?

Hope that's not too many questions and thanks in advance!