Yes, that's the rule I am questioning. The way I read it, you can't use it to drive traffic to an existing non-caching event, or to organize a post-event cache run, but those are mostly concerns about the commercial/advertising guidelines.
My question is more along the lines of whether or not this precludes using the event cache type to attract newbie cachers as well as allow old pros the ability to answer retreat attendees questions regarding the Caching 101 presentation, as long as the GC event description does not mention the artist's retreat.
Here's a slightly simpler scenario:
There's a large public park.
Pavilion A is being used by a free concert, but they're selling signed T-shirts and CDs. The concert promoters are goobers, and over ordered Ts. They don't have any way to take the unsold Ts away with them, so they've worked out a deal to give them to the park. These Ts are unsigned, and what that deal is doesn't matter.
You want to host an event at Pavilion C after the concert. The park rangers have promised to give you all of the left-over T-Shirts for free to give away as swag since they don't want to deal with them. This is what puts you in the grey area, since you now have the potential for attendee overlap between the concert and your event cache, but any concert attendees would have to have active GC accounts to count the event cache, and any cachers who are attending the concert are probably going to be there to support the band in the first place.
Hopefully this scenario is more cut and dried.
