How to make me feel like your expansion pack or downloadable content is just stuff that should have been in the original release but you were too lazy or cheap to finish it, and instead decided to charge me extra to play the game I already bought?
How about making DLC available on launch day?
Look at the 'bright' side - if we sell you a box with only part of a game in it and then sell you the rest of the game in five separate bits, it'll make it harder for the pirates to assemble the whole game! *sigh*
Of course, since I've gotten fed up with the Bioware style of generic plotting and the 'romance' scenes shown of this game were pretty cringeworthy, I'm not exactly a launch-day customer.