Stepping into any series halfway through can make for a confusing and disappointing experience. Every time a new Harry Potter movie comes out floods of people run to buy the original and start a marathon. Sometimes movie makers and game developers alike will push new content through just so they can watch the whole franchise benefit.
Instead of sitting by and hoping Gears of War 2 pushes people to buy further into the series the guys at Epic are providing a little incentive. Knowing a vast many of us are achievement whores, Epic has created linked achievements that when obtained in the first game will unlock content for the second. Epic confirmed these "linked achievements" at a recent panel questionnaire at ComicCom.
Therefore, anyone who already owns the game will get reacquainted with the Locust Horde and those new to the game will want to start where it all began. It’s a win-win situation. You get more Gears, they get truckloads of money. A few examples of these linked achievements are after the jump.