there's still a lot of legal "payola" stuff that goes on where the record companies offer free giveaways, and other things in order to get more airplay...usually all the decisions are made by the guys at the top of the conglomerate so they might not know who 50 Cent is or the Roots but they have more incentive because 50's company is giving them stuff (or they are both owned by the same company). What MTV plays probably has very little to do with the actual artist they play what gets them more money.