Part of the problem is with business is that they won't be prepared to spend money on promotion unless they feel it's worth it. Obviously, that's actually counter productive (after all, they might not be doing well simply because no-one knows about it- and a lack of propmotion isn't going to change that). And the promotions they did run were shown so infrequently, many people would have missed them (plus they were only shown on The Vault- they could at least have run them on the whole network of channels). I have The Vault on in the background most of the day, and I can say I only saw any of them a handful of times. It seems like most people who have found out about the repeats either did so through word of mouth or hopping across them by chance.
I also don't think the time slots helped, as many people would either be at work, in bed or have children who would most likely have control of the TV (Saturday mornings and weekday afternoons are obviously prime kids TV viewing times). The Sunday midnight repeat really wasn't the best timeslot either- after all, most people will either be in bed or out somewhere at this time (and if they are at home, they're likely too drunk to care what's on the TV). A weekday night slot (9-11PM) would have probably been best. Also, if they'd promoted it in the same way as they do with the competitions (promotions 3-4 times an hour, writing on-screen accross all 3 channels) that might have given them decent enough exposure.
It's very unfortunate though, the repeats were one of the only things I genuinly look forward to watching, and it really is a shame if they have been permanantly taken off.