Trustmark is known throughout the Southern states. Its headquarters are in Jackson, MS. While at S1, my staff members and I were given exceptional access to the bank's Customer Support Center to conduct numerous Depth Interviews and Observation.
Many Trustmark staff members were given time away from their jobs for lengthy interviews and to participate in formal usability testing of various S1 products (mostly Customer Support oriented), which were in various stages of development, ranging from html prototypes to almost fully functional systems.
Trustmark's online demo of its now live Bill Payment system, which is part of its S1 Online Banking (product geared towards Trustmark's customers), shows clearly how many iterations of usability testing and related customer research really pays off. It is noteworthy that the Vice President who was one of the major contacts with S1 was a VERY big fan of usability testing. He was also a big fan of using multiple Usability Testing vendors (in addition to my team) and distilling the results into a solid set of insights to drive design.