I did something like this when I worked for a group of radio stations. It gave us a source book of:
Events, Dates, Locations, Attendance avg #, Websites.....
Here in Centre County we have many anual events which bring in thousands of visitors. Many will be local - but many will be from out of town. I will need to do the research again but here are a few examples with Approx (made up but close) attendance numbers.
Grange Fair....Fall season.....Centre Hall.....5000 people....(insert website)
4th Fest..........Independence Day.....State College....50,000 people....(website)
Antique farm machinery......2x/year.....Centre Hall.....Thousands....(website)
Ag Progress Days.....Fall......outside state college....tens of thousands....website
Well, you get the idea. Since each one of us are probably better versed about the goings on in our own back yards than any 1 person in the state organization could be....this seems to make sense.
At work now but will add more to this OP as I can. I will take responsibility for starting the Centre County research and thread. BUT PLEASE feel free to add posts with info once I get it up on here and I will add it to the main OP.