Everything realshelby said is spot-on.
National rallies also do well when they are in a similar time frame each year but rotate venues. ... snip ...
It can always go back to a locale after several iterations. It would make it a lot more appealing to a greater range of riders imho.
I like the idea though
Attendance of "nearby" riders (relatively speaking) at any event will naturally be impacted by proximity. With that said, a four or five year rotation that is known in advance will foster greater attendance over the long haul as people can plan well in advance.
When my buddy and I did the CDT in 2010 we were at the end of a three year plan, the last six months of which was devoted to acquiring and outfitting the bikes.
Assuming I live long enough and the TDM factors are all equal, I'm already planning my soon after retirement last big trip.
A man has to have goals, you know?
Current rides: 2001 GL1800, 2014 DL650 Adventure; Gone away: 5 BMW's, 4 Honda's, 2 Suzuki's
"The object of life is not to be on the side of the majority, but to escape finding oneself in the ranks of the insane." -Marcus Aurelius