Do video clips in Showcases and TiVo Promotions take away from my recording time?

No, video clips for Showcases and TiVo Promotions are stored in reserve disk space used for other content. This does not take any of the disk space that is advertised for your DVR model. For example, a DVR with 80 hours of recording space has reserve space that is in addition to the 80 hours. The series four DVD provided by Sparklight has 500 GB and up to 75 hours of HD storage.