Quick way to rank up on call of duty 4?

Don't hack it takes the fun out of the game, and it is for noobs. If you want to rank up fast i recommend playing a objective type game like Head Quarters or Search, Both of these game types reward lots of EXP during and good bonuses after the match. In search for Call of Duty alone you are rewarded 50 exp per kill. HQ you obtain 5 points like every second when your team has the HQ capped. Objective matches offer more time and additional bonuses to help you rank up quick. My personal favorite is Hardcore HQ, i often party up with a full team and go to town, if your good at the game you can bring in good exp to help you rank up, and in HQ your getting lots of kills so challenges go by quickly, i hope this helps, and remember boosting is for pussies.