In any case, developers and publishers could cash in a bit already by allowing some sort of rental copies to be rented out (seeing how renting is now illegal over here). Charge a rather large sum for that, to compensate for the loss of sales that some rentals may cause (they may not like it that much, but at least it'll generate sales they otherwise wouldn't have gotten).
Don't see how they'd solve this used-situation though, although twesterm's move is probably the most logical one.







