I have read this article: http://www.mattcutts.com/blog/subdomains-and-subdirectories/
But I'm not 100% clear if moving my subdomain website into a subdirectory on the main domain would change anything related to SEO.
I inherited this structure:
The informational site gives a lot of good information on how to use the products we sell. The storefront is primarily used for the ecommerce function of selling the products, but there is a lot of info specific to the products on that site.