Securing long term partnerships

Hello, I just closed a deal to manage a quite large brand account on Amazon, my main concern now is that this partnership may only last 1-2 years and once the account has grown to higher levels they would just manage it by themselves. What methods, tips and tricks you can suggest to protect this deal and make sure they will stick with my company managing their account for long term? Essentially how can I make them dependent on me so it will be very hard for them to let go our partnership?

Brand management is going to have partner turnover. There will always be high expectations and, even if you raise sales 20%, they’ll want a 30% increase the next quarter. I think one good tip is to set reasonable expectations. Let them know all the activities you will undertake and don’t over-promise a sales increase.