You can buy attention (advertising)
You can beg for attention from the media (PR)
You can bug people one at a time to get attention (sales)
Or you can earn attention by creating something interesting and valuable and then publishing it online for free: a YouTube video, a blog, a research report, photos, a Twitter stream, an ebook, a Facebook page.
A great tool for explaining social media marketing to a group via the great David Meerman Scott.