I took a quick peak at the site and there were definitely some decent finds in there. The real estate financing calculator for example, looked pretty interesting. So does this template for Venture Capital valuation.
In addition, Docstoc, like Scribd, offers an easy way to share documents with your web visitors. Especially since they offer a way to easily embed those documents in your site.
I’ve embedded a handout that I’ve used at some of my speaking gigs, by way of example.
What’s the marketing hook here? Tenuous I guess. But I suppose if you have documents that you require customers to use on a regular basis you might consider embedding them using Docstoc. (Though you could just as easily put a link to a PDF on your server.)
Maybe also if you had documents you required for remote retrieval (you can flag any document as private), Docstoc might be somewhere you could store them.
If nothing else, it’s a fun, functional site – with some interesting potential, especially if the community around it takes off.