Internet Protocol Television (IPTV) is a promising technology which plays a key role in the triple play service over the next-generation networks (NGN). In NGNs, services are no longer bundled with transport networks; this feature opens a new window for researchers to develop innovative applications in the context of cloud computing. Specifically, in this research we demonstrate the concept of Communications-as-a-Service (CaaS) in cloud computing by proposing a network-based multicast IPTV audience measurement scheme as an application for IPTV distribution platforms. The scheme makes use of the standard Internet Group Management Protocol (IGMP) and Simple Network Management Protocol (SNMP), so upgrading the existing network equipments is not required. Compared with measurement schemes that collect data from the set-top boxes directly, the network-based scheme not only scales well when the audience is large, but also applies smoothly to heterogeneous network environments. We also discuss the potential services that the network-based IPTV audience measurement scheme can offer, and conducted laboratory trials in Chunghwa Telecom Labs. Although this work is by no means a technological breakthrough, we believe that this paper may shed some light on the research of creative cloud-based applications.