Big Cheddar

Roger Federer and Maria Sharapova in the Top 10:

The fellow Nike endorsers continue to flex endorsement power: the 27-year-old Federer and 21-year-old Sharapova are the only tennis players to crack Forbes' top 10 Best-Paid Celebs Under 30 list.

The Williams Sisters followed twins Mary-Kate and Ashley Olsen as 11th and 12th on the list of top celebrity earners under 30.

Serena Williams, who endorses Hewlett-Packard, Nike and Kraft, made $14 million, while 28-year-old Venus, who launched her EleVen apparel line last year, earned a reported $13 million.

Entertainer Beyonce Knowles tops the Forbes list , earning a reported $80 million during the past, which is nearly double the $44 million runner-up Justin Timberlake collected during the last year.

Four Nike endorsers rank among the top seven celebrities on the list: NBA stars Kobe Bryant ($39 million) and Lebron James ($38 million) ranked third and fourth followed by the fifth-ranked Federer, who earned $35 million and Sharapova, who came in at seventh (behind "Pirates Of The Caribbean" star Keira Knightley) with reported earnings of $26 million.