Tesco in-store TV not doing so great

This could be discouraging, given that the Tesco in-store TV installation was always one of the examples cited by people talking about established digital signage networks. According to this article at Brand Republic:

According to insiders, the chain is considering taking the channel out of its revenue generation team and plans to put greater emphasis on activity such as trolley stickers and window banners.

The original intention was for Tesco TV to divert revenue from TV advertising. But its sales house, JCDecaux, was forced to slash its rate card by 30% in early 2005 following poor take-up.

Major advertisers are understood to be unhappy about the network and have cited the placement and intrusive nature of screens as problems to be addressed.

It would be quite interesting to know what kind of ROI Tesco is getting (if they can figure it out at all), and what kind of studies/experiments they have done (if any) to determine how to best use the in-store networks.