dlc can be good stuff, but it also can be just profit.
so, im not sure if its a good thing or not.
i think its the way you, as a developer, go at it.
for example. if you do a mapping contest and choose some maps from it to release in dlc, so the maps become “official” i think its definately a good thing.
but if you go like, here are some extra abilities that you only get by buying dlc, or, heres a new, cool looking gun, which does nothing new or special but looks different, it would be a bad thing.
i think about dragon age oringins’ dlc, where you have to buy the dlc to get some new unique abilities and quest by buying it. thats just profit and a kick in the ass for every gamer.
but theres the upcoming dlc for shattered horizon for exampe (its acutally no dlc, its called something odd, a patch, with new maps and stuff, for free). and thats a good example of dlc.