It used to be that if publishers wanted you to pre-order or run out and buy a game the first day, they'd throw limited/collector's editions at you. But these editions generally aren't all that limited; you can still find Halo 3 the Master Chief "cat helmet" Legendary set a year later and for a lot less money. To reduce the chance that you'll wait and buy a game secondhand, publishers are mixing up their tactics by including one-time use codes for bonus content in the box. The latest game to try this is Gears of War 2, which promises a code for five extra multiplayer maps to join the 10 already in the game. Standing in line at a midnight launch event will also net you a code for a gold-plated Hammerburst assault rifle, though this sounds suspiciously like horse armor. This move is similar to what Call of Duty: World of War publisher Activision is pulling with its Day 1 Advantage, though more refined since you can still ostensibly get the bonus multiplayer maps months or years after launch as long as you buy the game new. It's more like what EA's Rock Band 2 is doing with its code for 20 bonus tracks (due to drop in the next few weeks). At first it seemed simply a maneuver to outshine rival Guitar Hero: World Tour's 86 songs, but now appears to be even shrewder move...
Some folks have been commenting that the ever-increasing DRM that publishers are putting on their games have less to do with preventing piracy ('cause clearly, if that were the aim, they're doing it wrong) and more to do with preventing resale. The used market is something that the games industry have always been crying foul about, in a way that other creative content industries just haven't (when's the last time you heard Paramount complain that they didn't get a piece of the $5 that Joe Bob paid to Sally Ann for her old copy of The Fugitive?). They're upset that I can buy Mass Effect for $60, then sell it to a stranger on Craigslist for $50, who can then sell it to his buddy for $40, and so on and so on, until at some point 6 guys have played a single copy of the game for $10 each, and EA only got that first $60 payment.
The difference in approach to mitigating this that the different publishers are taking is stark and very telling. EA (Spore) says, "You can only install off this particular plastic disc thrice and no more!!! Used market be damned!!!" Where MTV Games (Rock Band 2) says, "The first guy to buy this particular plastic disc gets these 20 songs as a bonus!" EA is trying to completely disrupt what is essentially a Fair Use transaction, to the detriment of their own customers, where MTV Games is actually offering MORE to purchasers of brand-new retail product. Imagine that, offering more value as an incentive to purchase. Couple that with their "We care so little about the used market for Rock Band 1 that for $5 we'll let you export all the songs to your hard drive and sell the game disc to whomever thou wilt!" move and it makes me seriously applaud MTV Games & Harmonix.
That said, Friends Don't Let Friends Sell (or Buy) Games at GameStop.