It's a good move. Cash flow is king in most businesses, so pretty universally, if you increase the risk or even just the timeline of cash payouts, you get more. It's an excellent negotiation dimension for anything involving money in my experience.
For my agency/consultancy, if a client wants a discount on the total investment, they can book a larger chunk of hours or pay upfront. More risk for them, less cash for us in total, but more reliable cash sooner, that's worth the discount. Cashback for quick payments is another common and simple example of this.
On the other end of the spectrum, if a client wants to delay payments to a later point in time to improve their short term cashflow, that will cost them more in the long run. Company shares, VSOP, revenue share agreements, success based fees and delayed payments with interest are some of the ways to implement this.
It all comes down to how you distribute the risks and rewards between both parties. Any good negotiation isn't haggling between two hard positions, but a shared venture to find a win win model. What you did there is renegotiate a deal that didn't work for one party to find one that worked for both.