Proof? According to Forbes Magazine there is a $105 million combined net income for 2007 alone among Elvis Presley, Charles Shultz (creator of Snoopy cartoon strip) and Heath Ledger (Joker in the last Batman movie)---all of whom are dead.
Elvis Presley died at the age of 42 but 30 years after his death he (his estate) was still able to amass $52 million in 2007. This is much bigger compared to the 2007 incomes of living stars like Madonna (with $40 million) or even Justin Timberlake (with $44 million). This is way, way bigger than the income of an ordinary Dabawenyos for that matter.
This was the second time that Elvis topped the list of top celebrity income earners both dead and alive. In 2006 Elvis had an income of $49 million. His high net income in 2007 was attributed to the extravaganza held at his home in Graceland, Memphis, Tennessee to celebrate his 30th death anniversary.
On the other hand, "Peanuts" creator Charles Shultz died at the age of 77 in the year 2000 but he was still able to amass $33 million in posthumous earnings thanks to a recent agreement inked between his heirs and the Warner Bros. Studios.
Ledger became even more famous posthumously when the previous Batman movie was shown thanks to a remarkable portrayal of Joker . He died in 2008 at the age of 28 but was able to amass $20 million posthumously.
On top 4 of the list of high income earners is Albert Einstein, who died in 1955 but left a legacy---not merely the theory of relativity---but the "Baby Einstein" concept which was developed into a full line of DVDs and toys for children. Thanks to Baby Einstein, Albert was able to amass $18 million posthumously.
Top 5 on the list is Dr. Seuss or Theodor Geisel, the man behind the movie "Horton Hears A Who" as well as several other childrens' books. Dr. Seuss amassed $12 million posthumously followed by John Lennon of Beatles fame with $9 million.