@jyxz if it's for Avanti they do a special deal which acts like a lottery - you pick a day and a morning/afternoon/evening slot and it allocates you a seat on a train of their choosing within that timeframe. You don't get to pick your exact train but the tickets are much cheaper. You can only book within 30 days of travel and not 5 days before. Not sure if it was that, I might have mentioned that one before. But I can't remember what the site is called

I think it's still Avanti-affiliated. I only use Avanti directly now - I'm silver now cos I travel to London so much.