The money which goes into second hand sales also goes to the developers, in an indirect way.
Why? Because some of the people who buy games first hand know that they can get money later by reselling their games. This gives them money to buy new games, and helps them justify the expense of $/€ 50-60 on a new game.
So much like the car market, the second hand market supports the first hand market.
On the other hand, it is true that developers are trying to stop the second hand market. I'm just not sure how successful they will be at keeping their prices unchanged even after denying their customers the option of reselling games. Also, games suffer very little degradation from use, unlike books and obviously cars. This increases the value of second hand games and decreases the value of first hand games, so there's a negative effect on developers from this specific factor.
My Mario Kart Wii friend code: 2707-1866-0957
