Applied for this position through a staffing agency. After receiving a callback regarding my resume and query letter, I went on an interview with the agency, which was possibly one of the easiest interviews I've gone on. They just want to make sure you're presentable. Dress professionally and be polite. That's all you need.
After getting a thumbs-up from that interview, I went on to interview directly with Cetera. This was also not very difficult. My interviewer asked some general questions, wanted to know about my experience with Excel and other computer software, and asked about my customer service skills. No trick questions or anything. Just be yourself.