system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why are DVDs region locked?

Simple question. Thanks to one of my favorite subreddits!
gpt
So that DVDs can be sold at different prices in different regions. Without it, someone could buy the DVDs in a cheaper region, then sell them in a more expensive region to make money. That would force the price of DVDs in the expensive region way down, and the maker of the DVD wouldn't make as much money both by selling fewer DVDs in the expensive region, and those DVDs that they do sell will be for a lower price.