In my experience, it hasn't been at all the case at all. The people who sign the cheques often speak a very different language and tend not to even use the product themselves...that's the job of their employees.
But when there are oportunities for ongoing payments, especially in the case where these are actually for service support (and they often are), the quality of your service support is what will be looked at when it comes to renewing the contract. And if there's no contract, the quality of your service support is the only thing standing in the way of them switching providers (unless you've implemented some type of lock-in).
From a service support point of view, the real question is does the sales force actually talk with the support team? A contract that can't be met isn't profitable.