I don't have any direct experience with this. But, in the course of working with the data from USOF's member survey, I've been intending to draft something like a Sponsor Kit or Media Kit for USOF (since a lot of the content could be derived from the survey data -- demographic info, income, travel habits, etc.).
So, if you want to be formal about documenting the value proposition for your poptential sponsors, you might want to put together something like
this or
this.