The most cost effective, time-efficient method for getting information from populations already connected to your business (employees, customers, etc.)
Print surveys are still effective tools for reaching a random sample or if your target population has a significantly high percentage of people who do not have easy access to or use computers.
When you need qualitative insights into the "whys" and "wherefores", focus groups allow you to go more in-depth into issues you know about and can lead you to insights you may have been overlooking.