With Grand Theft Auto IV's release date of April 29 fast approaching, Rockstar hasn't held back on heavily marketing its highly anticipated title. Eye-catching ads, billboards, and more are popping up in major cities across the United States and overseas. Some analysts are already predicting that GTA IV will sell $400 million in its opening week. That would beat out the current record of $300 million, which Halo 3 captured last year after a saturation of advertising and promotions leading up to its launch. So, how does the marketing strategy of the current record holder match up with what may be taking its place?