Al Nassr's become popular because of Cristiano. It's true ppl from all over the world know about SPL because he's more famous than other football players. They've got money they'll go to the transfer market to buy players which can help them win SPL.
Cristiano's signed a mega contract with Al Nassr he's staying for 2 years. I don't know they've given him shares in the company he would've stayed because other teams can't give him mega contracts. If Al Nassr don't win their SPL it won't be considered successful signing.
At least they won in popularity.
If they really want to become a champion, they have to sign top defenders because Al Nassr too focus in strength.