NBC is the first network to utilize a new system by Nielsen that will allow some of its programming to have both the original airdate and the encore aired later in the same week included in a single ratings report, rather than two separate reports. The first show to utilize this new system is "Heroes," which premiered Monday night and will have an encore run Saturday. Instead of two separate ratings, NBC has opted for one single one that will include viewers from both airings.

The ratings will not include duplicate viewing, and only add new viewers from the re-broadcast. But because of the system, final ratings for "Heroes" won't be available to advertisers, networks and the viewing public until Oct. 2 when Saturday numbers are typically released.