I would have to say it is extremely unlikely you can legally make duplicates of your (almost certainly) DVD. And no reputable company will make duplicates for you; they will require signed releases.
But I thought I'd add a bit about the difference between duplication & replication. Duplicates are made from ordinary Write Once discs, so they have all the same flaws. Duplicated discs are "burned" with a laser in a recordable disc drive. They take a significant amount of time to duplicate and there's a very real chance that some set-top players won't be able to read a duplicated disc. It doesn't happen often any more, but it can happen. So in my business, I guarantee the DVD will play or I will exchange it for a VHS tape.
On the other hand, a properly replicated disc will play in any set-top DVD player (with the proper region code, if there is one.) Replicated discs are pressed from a negative master disc (kinda like vinyl records) and this lets them be replicated much faster. But the replication master is far more expensive to create and the discs must be made in a factory setting. I've read, in several different places, that the replication master will cost at least $1000. So it doesn't make sense to replicate unless you need a large quantity (1000+) of discs that will play on any set-top player. Most companies that offer replication now offer duplication services as well, so you can find a number of companies to do the job.
To get a better understanding of the processes involved, I recommend visiting Disc Makers (www.discmakers.com) and browsing their web site. They have a large number of options to provide exactly the products (or services) required by smaller production companies. They even have a duplication service where they take your master & provide a marketing site to sell copies from 1 to 100+ at a time and send you the profits as they are made. So you can provide web sales even without a web site of your own.
So good luck (and don't be stealing just because you can.)
