Along the line of 'feelies', you can use microtransactions, which was how Sony originally wanted to distribute the next Gran Turismo for PS3. What they wanted to do was package a few tracks with a small number of cars and sell it cheap and then make people pay to download additional tracks and cars if they wanted them. You have to be careful with microtransactions, though and not make people feel like you are just milking them for money. You have to make sure people are getting good value for money, or they won't buy anything more than the basic game from you.