Set For Life - Scaleable Careers?

[Yuko Tanaka]

I recently finished (and loved) @Scott Trench's Set For Life. One point that I wished to understood more about, and that was beyond the scope of the book, was switching to a scalable career. Scott defines a scalable career as one that pays for performance against objective measures so you can achieve unlimited upside. 

What are some examples of scalable careers? Scott mentioned sales, and I'm wondering if the hive mind has any other ideas. Specific jobs and examples would be very much appreciated. One path I'm considering is becoming a Major Gifts Officer, which is fundraising for nonprofits. You might think that scalability would be severely limited at a nonprofit, but I've heard that there's room for considerable upside at certain nonprofit institutions with large endowments. Any other ideas?