Mar-Key: I recall him saying that the website can handle 150K. This doesnt mean that the entire process can handle that type of influx of subs all at once! There are many variables with the influx of a large amount of subs such as inventory, DC's being overwelmed with distribution, etc.
People do need to understand that the company is not going to make inventory committments to handle 300K people until they show the numbers raising near that high. Also it is a very difficult thing to predict the inventory levels for the future. There will always be peaks and valleys when it comes to inventory and the same thing does happen with Netflix as well.