Extra Credits - Free to Play Is Currently Broken - How High Costs Drive Players Away

Unless it's done right, ala Mario Kart 8, but those are in the extreme minority and very few and far between.

Even then, though, it could really be classified as an unfinished game. They released the game without some of the features intended for the game. They almost certainly had been working on the DLC prior to the game's official release, and it probably hasn't taken the full span of time up until now for it to have been finished. Instead of waiting a month or two to add the rest of it, they released the game earlier to make revenue sooner as well as add an added cost for the game. It's a smart business practice, really.

Obviously though that's just a matter of perspective and isn't necessarily applicable to all cases. I can't know for certain whether or not MK8 falls under that umbrella. For all I know, MK8's DLC is a completely fair purchase. The line between DLC and expansion packs does sometimes blur.