Many times I came across workshops or seminars and realized it was too late to register because the date for the event had already passed. After asking around I discovered that the sponsor only advertised locally.
Don't think like that.
I know a lot of photogs that will travel in the tri-state area (NY/CT/NJ) just to attend a workshop. Soon after creating the Long Island Photography Meetup a member joined who lived in New Jersey. I could have blocked his membership but what's the point? His gallery was awesome and he was involved online. And eventually he was the first arrival at Meetups.
Taking this into consideration, it's prudent to advertise bigger than you think you are. If you're a local club, advertise your event further than you would travel. There's folks out there that are willing to go the distance.
SureLine Studios created this flier for LIPM's
I have a dream that one day on the red hills of Georgia the sons of former slaves and the sons of former slave owners will be able to sit down together at the table of brotherhood.