As someone who lives in both worlds, I've noticed that SMM and SEO people are often isolated from each other. SMM people don't even know names like "Danny Sullivan" and they don't even know about PubCon or SES. And yet they still add great marketing value to the online businesses that they work with.
On the other side, many SEOs have never heard of the SAMMY Awards, or OMMA, or even the Forrester Wave quarterly report. And yet a good SEO still brings in awesome value, too.
Bring the two worlds together for your online business and you've got a very good thing going.