This Points Card lets you buy XBLA (Xbox Live Arcade Games) off the Xbox Live service. I've bought Prince of Persia Classic so far and I look forward to buying another game called Exit on XBLA.
The problem is most XBLA games come in multiples of 400 points. So you can buy just 1 800 points XBLA game or 3 400 points XBLA games and you'll be a 100 points short in either case for 1 more title in which case you will have to buy another of these cards for those extra 100 points. For example: I bought one of these 1500 point cards to buy POP classic in June 2007 for 800 points. I now want to buy Exit which costs 800 points but I have only 700 points and I have to buy one of these cards again for the extra 100 points and the remaining 1400 points will be eating dust.
Of course you can use the card to do buy silly stuff like “picture packs”, “themes”, “change gamertag”, etc. but it is something I don't want to spend my money on.
The points available on this card is either a money making gimmick or some one at Microsoft did'nt do their home work while shaping such a product for the NZ market (you can get a 1600 points card in the US). Alternatively you can buy points from Xbox Live directly using a Credit Card but I don't have one.