Sometimes it really isn't whether you win or lose, but how you play the game, that's important.
The internet has changed multiplayer games; not just how we play them - although that's the most obvious change - but also how we derive enjoyment from them. No longer is the thrill of victory enough, now that victory has to be part of an ongoing journey, and when it isn't, a lot of the fun goes out of the experience. In Issue 304 of The Escapist, Ben Carlander says that buying a sequel to a game helps us keep multiplayer fun by giving us new journeys to embark upon.
Turn back the clock to the years of arcade gaming. Multiplayer then meant you and your friend kicking each others' asses at Street Fighter ... [But] things are different now. Multiplayer games aren't as personal. You're playing several faceless people that you've never met, and you're playing them over the internet. Defending your honor often means pulling out better weapons, perks, and streaks than your opponent, but it can also mean finding a good camping spot.
It's the leveling-up part that seals the deal ... Suddenly the multiplayer has a goal, a goal that you can reach if you just play long enough, a goal that, once obtained, divorces the game from a lot of emotional investment. If the experience becomes about leveling up, then once that stops being possible and there's nothing else to do other than just play the game, playing has lost its purpose.
That's where what I like to call the reset button enters the picture. An offer comes along to start anew. As long as you buy this freshly-released game, you can get to relive the excitement you felt when you first played the previous one. And not just you, but everyone else will be able to reset their game, so you won't feel like you're alone in experiencing this. It's a new adventure for everyone!
Even if the gameplay of a sequel is almost identical to its predecessor, having a new journey can keep the experience fresh. You can read more about it in Carlander's article, "The Reset Button."