P2P file transfers and streaming have already seen a tremendous growth in Internet applications. With the rapid growth of IPTV, the need to efficiently disseminate large volumes of Video-on-Demand (VoD) content has prompted IPTV service providers to consider peer-assisted VoD content delivery. This paper describes Zebroid, a VoD solution that uses IPTV operational data on an on-going basis to determine how to pre-position popular content in customer set-top boxes during idle hours to allow these peers to assist the VoD server in content delivery during peak hours. Latest VoD request distribution, set-top box availability, and capacity data on network components are all taken into consideration in determining the parameters used in the striping algorithm of Zebroid. We show both by simulation and emulation on a realistic IPTV testbed that the VoD server load can be significantly reduced by more than 50-80% during peak hours by using Zebroid. Categories and Subject Descriptors H.4 [In...