Why spend Billions on IPTV?

NBC is rolling out DotComedy.com with Letterman and SNL shows. ABC has shows on iTunes. Even AT&T has its U-TV. Starz has been available on demand on the web for a long while. So, why are the telcos spending so much energy and money on IPTV? Why get a franchise when you could just give them a big pipe and let them download what they want on a TiVo you sell them????