Given that they're searching for volunteers, it makes more sense to appeal to the general population than to business people, doesn't it? (As a non-business-person, certain practices in SEO sound to me much like Dark Arts, though they exploit misfeatures of search engines' (rather than human minds') algorithms.)
I wouldn't say so. For one thing, there's a substantial overlap between "business people" and "the general population," especially the portion of the general population that's likely to take volunteering for SIAI seriously in the first place.
A lot of "white hat" SEO is just a matter of making the connection between search engine algorithms and what's actually being looked for. Appropriately tagging pages to associated them with relevant subjects, asking people who are genuinely fans of your site to link to it on their site, making yourself visible on the social web, etc. . .
Here's the new thread for posting quotes, with the usual rules: