Assuming that the business has any form of online presence–then the obvious answer is yes.
I work with social media agencies and the main way we improve both our online presence and our conversion from audience to client is through masterful optimization of our SEO.
We make sure that the blog posts that we pump out are informational and in-depth enough to garner organic readers. Our social media platforms, albeit riddled with nofollow links, are also a huge funnel towards our site. Plus, we have killer proposals that close out deals quite nicely when paired with our socmed, SEO, and marketing efforts.