If your sales aren't high, you are dismissed before your 90 days are up. I worked in Credit Card Customer Service, and if you're not meeting your goals, you are penalized with reprimands and meetings with HR. The job interviews never said anything about sales goals, and in fact only stressed customer service. When you get in on the floor, it is only about meeting sales targets. CS takes a real backseat.
Incentives for meeting Sales Goals
High Sales Driven Customer Service Sector