In the age of digital distribution, developers are now adding more and more content after a games original release. Some companies use this opportunity to address problems found in their game. Others use it to try new things in their game (Burnout Paradise). However some companies use dlc as an excuse to make gamers pay for content on the disk or content that should have been on the disk to begin with (Resident Evil 5 that means you). This isn't saying that dlc is all bad or that dlc has had an entirely negative effect on the industry. There are some developers that are just making games for a quick buck, so of course some companies  are going to see dlc as another chance to make easy money. But for every bad publisher out there trying to pull a fast one on the consumer (namco), there's a good one that's genuinely trying to please their fans and put out dlc that they will enjoy (bethesda minus the horse armor). So it's clear that dlc is going to be around for a long time so hopefully more developers will start using it as a way to better their game and expand on it rather than use it to make some easy money.