One piece of free advice I give to visitors to Hong Kong is to buy an Octopus card when they arrive at the airport, and then hand it back just before they fly home. You pay lower fares on the MTR and KCR and can get special discounts (mainly on buses and the Airport Express), and of course it means you don't have to fumble around for unfamiliar coins every times you want to travel somewhere.
However, it seems that rather too many tourists have been doing just that, and it's affecting the profits of the Octopus company. They say that the cost of processing refunds and updating the cards means that they lose money on any cards that are used for a short time. I think they really mean cards that aren't used very much, because they receive a small fee from the transport operator (or other organization) every time you use the card, but I suppose it amounts to much the same thing.
So now if you return an Octopus card within 3 months, they will deduct HK$7 from your deposit to cover their costs.
However, let's be honest - when it comes to parting tourists from their hard-earned cash, HK$7 is not really a significant amount. Never fear, they have thought of another way to get a larger slice of the cake. Yes, they will sell you a special tourist Octopus card for HK$70. It's exactly like a normal Octopus card - well, except that there is no stored value and it "holds no deposit", so you are actually paying HK$70 just for an Octopus card that you is yours to own for ever.
Now, it may well be that for some visitors to Hong Kong, an Octopus card with a full colour photograph of some Hong Kong landmark or other is just exactly what they were looking for, and they will be delighted. It'll look lovely next to your 10" high figure of the Queen of Hearts and all the other crappy souvenirs you have acquired.
I am more concerned about the small minority who want an Octopus card so that they can, er, travel around Hong Kong. These poor souls might believe that paying HK$70 for a tourist Octopus is attractive compared to paying HK$150 for the normal card. Well, it isn't. I just hope that someone points out to them that because their HK$70 hasn't bought them any stored value, they will have to add value (a minimum of HK$50) before they can use the card on public transport. So, get smart, ask for a normal card and save yourself HK$63.
In true weasel fashion, Octopus point out that you could always use the card on a return visit (because they are valid for 3 years). Well, yes, but if you bought a normal Octopus the same thing would apply, and you wouldn't have to pay the HK$7 penalty if you returned it on your next visit. So get a normal Octopus card.