Or, being lied about, don't deal in lies,

There will be rumors about your business at all times.
You'll always hear that you're going to lose your best people, your best customer, your best supplier.
The best way around this? treat them well, make sure that they have no reason to leave you.  By the time you're asked to re-bid, it is already too late.
I can say ethics, or being a good person should prevent you from dealing in lies, but if that worked, you wouldn't need to hear it from me.
For those of you still on the fence, here's the answer.  People have long memories.  And they will remember your actions from the past.
A good story gets repeated 3 times, a bad story, 10.  This true from customers, suppliers, employees, and any/everyone you interact with.
Your reputation will follow you from business to business, start-up to start-up.  How you've handled yourself in situations will become known to others.