How do you deal with sales commissions?

Being the slow time for us this winter, I have this one great employee who has a long background in selling (use to work for banks and other companies selling products and offers). I decided to put him a few days a week on finding commercial and store-front clients (window cleaning and high-pressure). He’s normally paid 15$/hr to do the manual job. For a few weeks now, he has bring some new regular clients and a few one-off jobs. Due to the “low” quantity he brings for now, we agreed on a commission based on closes as follow: 30% of first invoice for regular clients (weekly, bi-weekly, monthly clients) and 3.5% of invoice for one-off clients, on top of his hourly rate.

Now, in 2017 I want to open valves and expand massively, but I fear that my commission ratio is wrong and feel it will sucks all the potential profit. I.e: If we make $1,000,000 in sales, I wouldn’t want to see $300K go out in commissions – seems ridiculous. Do you have any suggestions for me? What would be a good incentive to give so he can meet the weekly target and be motivated to continue?

Any help appreciated here.

simple have a sliding scale, work out what a fair pay is say weekly and once he meets that in commission it drops by say %5 for the next $100 than drops by another 5% and so on,

I pay my sales guy 22% of the first invoice and than 5% there after for a repeat client.

for a one off job say a house wash i pay $12% of the invoice as commission , My profit margin is 31% so still profit left over