Share 'Realtor and Lender networking value for HERS raters?'

I'm having a hard time wrapping my mind around the benefit of investing time/energy into developing a strong  network of Realtors and financial lending institutions.  Aside from markets where ratings are required when property changes hands, what's the value? Is it just so they can refer you as a resource to their clients who are looking for practical energy upgrade ideas or for energy performan…