Yup, licensing.
You designed the kit, therefore it's your intellectual property.
You could ask for 5-10% of the gross revenue.
Gross, not net profits.
Here's why:
With net, they can deduct the cost of fullfillment, material costs, refunds, overhead, salaries, rent...
...and you'll eventually end up with nothing.
Clients like to tell stories about bad economies and suppliers that get more expensive week by week.
To the IRS, their ex-wives, and to you, their net-profits will always be next to nothing.
You designed the kit, therefore it's your intellectual property.
You could ask for 5-10% of the gross revenue.
Gross, not net profits.
Here's why:
With net, they can deduct the cost of fullfillment, material costs, refunds, overhead, salaries, rent...
...and you'll eventually end up with nothing.
Clients like to tell stories about bad economies and suppliers that get more expensive week by week.
To the IRS, their ex-wives, and to you, their net-profits will always be next to nothing.