From a rider (consumer) perspective: there's probably an inverse relationship between repeating/established events and the need to spend superlative efforts in promotion. First year/inaugural events - need to get the word out. If the venue is good, repeats the same time each season, and word of mouth gets out to the community, racers start incorporating it into an annual plan, and look for registration to open on places like BikeReg, although late reg. seems to be the norm in recent years, unless people see that capped events are approaching their limit. In this sense, repetition is good, where people keep coming back for the same "product", if you will.
Looking into metrics on repeat participants is an interesting point. Thought I saw a lot of kits from LI based teams this year that I don't recall seeing the prior 2 years the race has been the 45 mile format (although I could be mistaken on this). From a "local" racer standpoint, I don't see where an event like the 45 involves travel/cost/logistics to make this a bucket list or "one and done" type of thing.
Would be interested to hear opinions on overall attendance trends at H2H events throughout the season. Early spring March/April where weather can still be iffy, 18" snowfall the week prior, and it appears there's a lot of interest. By the time July comes around, field sizes decline, and it seems there's less and less buzz and chatter pre/post race on message boards. Did anyone do the last H2H in Port Jervis? Near zero banter, and no dedicated thread topics. Total burnout by mid-July?
Some local/regional events wax, wane, and die off, while others continue, without any significant change in venue or promotion. No clue what the magic combo is.
American Idol, Survior, etc. may get too formulaic to keep interest (are these still on TV?) and I would doubt these are at all interesting in reruns. Jeannie, Seinfeld, etc. are classics. Even if you haven't seen them in a while, you may actually sit and stare a while surfing thorough cable.