Purpose: The purpose of this study is to investigate the use of co-browse in live chat, customers' question types, referral to subject experts, and patrons' usage patterns as experienced in the virtual reference (VR) chat reference services at Texas A&M University Libraries. Design/methodology/approach: Chat transcripts from 2005 to 2007 were sampled and analyzed by peer reviewers. Statistical data in that period were also examined. A set of methods and a pilot study were created to define the measurement components such as question types, expert handling, and co-browsing. Findings: Co-browsing is used in 38 percent of the sampled chat sessions. The Texas A&M University live chat service group considers co-browsing a useful feature. Of questions received on VR, 84 percent are reference questions. Only 8.7 percent of the total questions or 10 percent of the reference questions need to be answered by subject experts. The use of VR increases dramatically in the past two years at the Texas A&M University. The findings also reveal users' logon patterns over weekdays and weekends. Originality/value: The study contributes and advances understanding in the role VR plays in a large academic library and the role co-browsing plays in VR services. The study also provides a comprehensive method for transcript and usage data analysis. It is believed that a similar methodology may be replicated elsewhere by other institutions engaging similar services or evaluation. © Emerald Group Publishing Limited.