In a sale
The second bite is paid when the buyer sells the business again, on the stake the founder kept. With a capable buyer it can exceed the first sale; with the wrong one it can be worth nothing. That range is why the size of the roll, and the choice of buyer, matter more than the promise of a second sale.
Where it comes up
The Go-To-Market Analysis (GTMA) builds the file a buyer would build on your business, before a buyer does.