Being likable is be critical for career success, but that doesn't mean you have to be nice, Lance Haun writes. As an example, he pointed to a likable colleague. "I know Sharlyn isn't nice all of the time," he writes. "How could she be? If she was nice in contract negotiations, she'd be out of business. If she was nice in client consultations, she wouldn't be able to tell them how they are messing up."