Upwork's tiered commission system where freelancers pay 20% on the first $500 earned with a client, which drops to 10% once earnings exceed $500 with that same client.
"For the first $500, if you're an Upwork freelancer, you land yourself a new client, the first $500, you're going to pay a 20% fee... Once you pass $500 of earnings with a single client, your fee is going to drop down to 10%."