Tyson Fury is a huge WWE fan and he hasn't shied away from making it clear that a big part of why he's facing Braun Strowman at Crown Jewel is because he's a lifelong fan and his kids love the product. However, you'd best believe that the champion boxer isn't appearing for free!
According to multiple outlets, Fury is earning around $15 million for joining the WWE roster for this storyline and it's a figure that could rise depending if the company decides it's worth having him return.
Fury has even teased a confrontation with Brock Lesnar or Cain Velasquez and that would definitely be a match it's easy to imagine WWE promoting for WrestleMania. The company has brought him in at a time when SmackDown moved to FOX and the reset button was hit on RAW for a "season premiere" so they're clearly hoping he increases mainstream interest.
That's definitely happened but it's hard to say how much of an impact it's had on ratings.