Not to toot my own horn (it's busted), but I just wanted to illustrate the possible effect of having a dedicated social media specialist in your company. I worked at FIJI Water from 2/26/09 to 5/22/09 in my contract social media intern role...

I'm not saying that social media contirubted in the spike of unique visitors to fijiwater.com, but it may be a strong factor. With enough research, social media probably would be attributed as a primary factor. So all you companies -- get someone who wants to go out there and outreach, have conversations, and create connections with communities all over the 'Net. It probably won't cost you much ^_^