"Apparently this is a Sony Europe rule – you cannot have expansion packs be available on PSN and at retail. You can in North America, which is why we have both here.”But a spokesman for SCE UK has gone on to clarify the situation with his own comments:
“It has been SCEE's policy since the launch of the first PlayStation in 1995 that all discs must carry a PlayStation executable – i.e. they must be game playable discs."Does make sense that they would take this approach to insure as little returns to games stores as possible. Although it typically says on the box nothing can be more annoying than getting home and being told by your system that you need the original game to play what you’ve just bought. Thank God for genuine updates like Super Street Fighter IV and Resident Evil 5: Gold Edition.
“This policy is in place in order to protect consumers from mistakenly buying discs they can't play due to unknowingly not having the original version."
"Therefore, by including a PlayStation executable with sufficient DLC content, we can provide disc-based versions of content that offer a fantastic user experience e.g. LittleBigPlanet Game of the Year Edition or GTA IV: Episodes from Liberty City.”