Gray and Keys, who signed for the commercial radio station in February, have increased listenership by 100,000, figures suggest.
However, their big-money deals have resulted in TalkSport losing 13% in profits year-on-year, parent company UTV Media revealed.
TalkSport boss Scott Taunton said of the pair: "There's no-one who's a football fan who questions their knowledge of the game. They've brought to the station a contact book that we've never had before.
"Most presenters or reporters can get an interview with Wayne Rooney but they have him in the studio for a whole hour."
Presenter Keys resigned and pundit Gray was sacked by Sky in January this year in the aftermath of their off-air comments about female assistant referee Sian Massey.