Yes, I can and I do understand that it would be difficult for a company to sustain such losses but they could certainly have handled the fall-out better and treated people equally. It wasn't that this was a £1 offer for a month that went through at £10 for a year - once on the purchase page there was a choice £1 for a month or £10 for a year. It wasn't as if people were exploiting a bug in the system, this was presented as a genuine offer. FindMyPast have acknowledged that it is entirely their mistake.
It wasn't advertised as a genuine offer by FindMyPast, it was posted on here, and possibly elsewhere, and then reposted on various other Facebook pages and probably elsewhere. If you check the first page, someone did ask the OP where they saw it and they didn't respond at that time. The online voucher sites had obviously picked it up from somewhere and reposted. The fact they provide a percentage of how many people were successful at using the code does show its unlikely to have been a genuine advertisement placed by FindMyPast. Most of these sites do seem to repost the offers they see.
The offer code was advertised on the FFHS Ezine in relation to £1 offer, although that didn't specifically say for one month, but considering the number of £1 for a month offers that there have been this year, most people would realise that was probably what it was for. OK most of us weren't aware of this until after the facility was pulled but that doesn't mean that FindMyPast advertised it as such.
FindMyPast appear to be relying on the fact it was a misprice on their system and some contract law that appears to allow them in certain circumstances, because it was such a big discount, to argue that it would not be reasonable to expect them to have genuinely made the offer. The fact they never actually advertised it themselves, but it was their system applying the code to the wrong subscription level, would probably work in their favour. I've been trying to find a link to the appropriate legislation to do with mispricing on the web to see what it actually says but haven't been able to find one as yet. However, the Which article that a RCer posted on a previous page of this thread is a good overview of the subject and there are other webpages that discuss it, although these apply to the sale of goods and not services. They do seem to say that in the case of a misprice, all orders have to be revoked as nobody should be able to benefit from the problem. This is most probably why they have revoked not only the subscriptions of those of us who used the code to extend an existing subscription which would start at a later date, but those who didn't have a subscription and obviously started to use it immediately.
I know FMPs T&Cs state that once you get a confirmation email the contract has been accepted, but the crux of the issue will be what the mispricing rules in the legislation actually say about this and how they would likely be interpreted by a court if it ever went to court. The fact that the mistake, and it was that, allowed far more people to benefit from the big discount that the normal £1 for 1 month offer would, probably would act in their favour as they would argue that no reasonable person would realistically expect them to discount an annual subscription to such an extent (there hasn't ever been such a large discount on the annual previously, only a 50% discount) and take such a loss.
If anyone really wants to find out, then contact the CAB or a solictor and ask, but to those overseas please note this is covered by the law in England as that is where findmypast itself is based (its their parent company which is based in Scotland).
This is simply my interpretation of what I have read in relation to this, I'm not a qualified solicitor.
Don't get me wrong, I don't think FindMyPast have really dealt with this in a good way. There has been no public comment that they had an issue, its all been limited to individual emails to people affected and I do think their emails outlining why they were revoking the subscriptions could have been much better, not least stating the appropriate legislation which would allow people to satisfy themselves as to what it does actually say. I don't think their T&Cs are that good either, so much for reducing jargon. I suspect there will be a major rewrite of them at some point to cover their backsides more easily if such an issue arose in the future.