Digital release on PSN Store and XBL would increase sales!! It is also great for those that might not find a copy at retail and save more money too.
Digital release has many advantages:
1. infinite supply, so it's easy and fast to buy one.
2. usually cost less than a disk copy.
3. easy and fast to replace. Corrupt file? Redownload it for free!
4. Usually a fully installed game on harddrive loads faster than partial install.
5. Digital market is more accessible globally and faster to buy and start playing than having it delivered or searching for a local store that has it.
6. Since digital market covers a wider market of buyers, it would help KOFXIII receive more customers and sales.
There are parts in the world where KOFXIII might not be sold, but with online access, more people will be able to buy and play it!
Since SNKP is cashing in on the Neo Geo Station series, I would think a KOFXIII digital release on PSN and XBL is possible perhaps at some point.