"Green beans store the best in cooled airtight containers, and can easily last in this state for a year without losing flavor" -
http://en.wikipedia.org/wiki/Coffee_bean_storage.
If they are only harvested once a year and then shipped around the world they will be more than a year old by times. I don't notice a taste difference according to the season, nor do I know what year the beans were grown (but I doubt they are thrown out when new ones arrive) so I go for the savings on shipping. I have been doing it for years so am uncertain where I got the idea the flavour become more intense with shrinkage. On the other hand the difference in roasted beans is noticeable after about five days.
Edit
Here is one reference although hardly pertinent to my situation: "It is a little known fact that certain types of coffee beans improve with age. This is because the aging process produces a less acidic taste with a more well-balanced flavor. For the most part, the aging process for coffee beans last between 2 and 3 years. However, there are several specialty coffee stores that offer unroasted coffee beans that have been aged for a longer period. One example is the famed Toko Aroma, which is located in Bandung, Indonesia, who age their unroasted beans up to 8 years." -
http://www.ringsurf.com/online/2091-aging.html