​Jason Fried, co-founder of 37signals:

But big customers make me nervous. After all, he who pays you the most has the most control over you. And we don't want any one customer to control us. What's more, it's not fair to your other customers if you're putting most of your energy into pleasing the big spenders.

Excellent insight. Read the whole thing.

And of course, that danger lies not only with big spenders. You could just as easily let your company or product vision be controlled by voices with a megaphone. You could spend all your time trying to make them happy. Who's got the vision for your product anyway?

Love your customers by spending your energy making a truly great product. They deserve it.