Gigwell supports various deal-types outside of landed/ all-in deals.
Flat Guarantee
Versus
Plus Bonus/Percentage
Straight Percentage
For back-end deals, you can add itemized buyer/promoter expenses (planned vs. actuals) and ticket scaling to calculate your total deal potential and post-expense profits. Once you receive ticket finals, you'll be able to invoice for the exact back-end amount you're owed.