83% of Tivo users who watched an episode of Mad Men that they had recorded fast forwarded through the commercials

"AMC's Mad Men saw 83% of its timeshifted audience fast-forward through its commercials, compared to a genre benchmark of 73%. Comedy Central's South Park similarly showed fast-forwarding of 66% compared to genre average of 55%.
NBC's 30 Rock and sitcoms in general were the exception with only 64% fast-forwarding compared to a genre average of 66%."
Source: TiVo press release, 23rd September 2009