I think with regard to ecommerce, once that kicks in and becomes significant, you are going to want to be shipping one and two discs. You're going to want to keep inventories as low as you can. Not surprisingly, short runs can have significantly higher per-unit costs than typical long runs. Although no replicator would go on record with exact figures, most agree that short-run costs can go as high as four or five times the cost of a typical order. If you can save your stampers and screens, it may not cost as much as others say.
Brokers can also play a part in getting a replicator to accept a short run.
However, be careful when selecting a broker. The term broker has some negative connotations, and replicators may not want to work with them. Even the definition of broker is changing. A broker, today, might be able to bring different facets of the industry together, for example, replicators and distribution. Inevitably, as the nascent DVD universe evolves, the media, its uses, and the means to get it to market will change.