In general, PSN games (like titles on XBox Live Arcade and whatever solution Nintendo finally arrives at for original games) are less investment-intensive and wouldn't fly at full retail price. They're generally lower-budget, quicker to develop and less deep than manufactured SKUs.
That said, games like Calling All Cars and FlOw are truly excellent for what they are, and the prices have been right. I wouldn't be surprised to see this end of things become the big growth engines for small publishers on all the next-gen connected platforms. Investment risk is lower, production and distribution costs are minimal and the games have generally been worthwhile.
You can do a lot of good gaming with $50 or $60 worth of downloadable games, compared to buying a full-scale title.







