I will keep expanding...FOREVER.
MMOs are well-known for having never-ending and ever expanding content. While there is a story that holds the universe of the game together, the game itself never ends unless the player wants it to end (by not playing the game). Since there is no actual ending to the game, there is always more items to get, or something you haven't done, even if you hit the current end game section. New content and bug fixes are done through patches. Basically, more coding to expand on the game that already exist. With the current consoles having the power to do just that, developers are using it to their advantage to produce more content to please (or potentially displease) the fans. With technology moving at the pace it does, it was only matter of time before downloadable content came about for the consoles.
Console games are built with an ending in sight. They always tell a story that conclusively ends in some way, even if the game ends with a cliffhanger. There may be lots of optional content, but the content is already included in the game. Obviously, the big component downloadable content allows for console games, is that the games can be patched, fixed, and expanded upon just like MMOs. You no longer have to be stuck with a game with a certain glitch (unless you want to use the glitch yourself). Universes can be expanded upon through single player experiences, like what Gears of War 3: RAAM's Shadow did. This is the kind of DLC that many would want. It expands on the single player experience for a game that has been out for a little bit of time. Imagine if the Gears of War example was used on even older games. While Gears of War 3 provides a good example of expanded single player content, there are times where consumers feel cheated out of good DLC.
PLAY AS ME!
The backlash CAPCOM received from leaving Jill Valentine and Shuma-Gorath as DLC was incredibly strong. The reason for the intense backlash was that the coding for the characters was already on the disc. The two characters could have been regular unlockables, but CAPCOM decided to just lock the character data unless you paid for it. By locking what could have been regular unlockable content, the player is left with an incomplete game. Another strong example of unnecessary DLC includes the Batman Arkham City challenge maps that include Nightwing. It would have been great to see Nightwing's challenge maps, which were released soon after Arkham City, to have been regular rewards for completing other parts of the main game. Lastly, there are the game of the year editions that are released at discounted prices with DLC included, and lots of the single player games include multiplayer DLC.
Games that focus on multiplayer, such as Call of Duty and Street Fighter IV, are able to capitalize on downloadable content more. Although Call of Duty has the potential to release single player expansions, the market the game caters to is multiplayer, so they end up offering lots of multiplayer expansion packs. Street Fighter IV just offers some fun costumes. The new and offered content only helps to keep the game's fire lasting longer. The extra content does not come off as something that is necessary. It would be nice to play in Cody's revamped classic outfit, but you don't need it in order to enjoy the game.
Cody's original outfit (top) and one of his many downloadable ones (bottom). Which one do you want to use?
While DLC certainly has lots to offer, it needs to be done right in order to make the best of it. Companies are going to use DLC in any way they can. DLC is certainly here to stay, and it's a great way to keep the life of a game going. Just remember that DLC is always optional, no one is forcing you to buy it.