Minimum Revenue Threshold for Commission Structure: Is This Typical?

I’m starting with a new agency, and I’ve come across a commission structure that includes a minimum sales threshold. Specifically, it states that for every new business deal I close, the first X amount of revenue will revert to the business, and my commission percentage will apply to the remaining amount (after subtracting X).

For example, if X is set at $1,000 and the total revenue from a deal is $20,000, I’ll earn my commission on $19,000. Is this kind of structure common in the industry?