Posted: 04/05/2016 at 13:34
They say that they will tell entrants when it is, cougie. But basically I think they will, if they're in any way a legitimate business, have costed it and worked out how many entrants they need. If they get that many expressions of interest (you can't enter straight away, but have to put yourself on a list) they will go ahead and organise it. If they don't (which seems likely), they don't have to organise anything because it's a secret anyway so no-one will know they didn't. All they've had to invest so far is the cost of hosting the website.
I think they'd have better luck with a 'secret 10k' or something that would appeal to a target market of people who do a bit of running and think this sort of thing is cool - marathons take a lot of commitment and I can't imagine the bit of the Venn diagram that includes 'people willing to commit themselves to do a first-time autumn marathon with no details' and 'people who like the secret event concept' is that large.