Reggie Bush and Kim Kardashian dated on and off from 2007 until they broke up for good in 2010. When Bush first met Kardashian, he was the more well-known of the two.
Bush was a Heisman trophy winner in 2005 out of U.S.C. and was taken second overall in the 2006 draft by the New Orleans Saints.
Bush was one of the most in-demand athletes and signed a large endorsement deal with Adidas right before the draft.
I believe that once Kardashian and Bush started to date, it helped to raise Kardashian's profile and made her more of a household name, since Bush was so popular. After Bush won Super Bowl XLIV in 2010 with the Saints, he and Kardashian permanently called it quits.
Following this breakup, it seemed that Bush's popularity and luck took a hit. In 2010 he was ruled ineligible for the 2005 season due to NCAA violations and gave his Heisman trophy back. His violations were part of the reason why U.S.C. received strict penalties and had to miss two bowl games.
In the summer of 2011, Bush was traded to the Miami Dolphins, where he's had two decent statistical seasons but hasn't experienced team success.
Overall, after Bush and Kardashian broke up it appears that their overall popularity went in opposite directions.