In the two weeks since Fox News has switched Greta Van Susteren to an earlier hour, Sean Hannity to a later hour, and inserted Megan Kelly after Bill O'Reilly, all prime-time slots have had better cable news viewing percentages.
Ratings in % of cable news viewers (P2+):
. . . . . . . . . . 09/30 . . . . . 10/07 . . . . . 10/14
Bret Baier . . 45.3% . . . . 46.5% . . . . 47.6%
Greta . . . . . 43.3% . . . . 48.8% . . . . 46.9%
O'Reilly . . . . 54.1% . . . . 58.2% . . . . 62.2%
M Kelly . . . . . . . . . . . . . 52.3% . . . . 54.7%
Hannity . . . 42.3% . . . . 48.5% . . . . 49.1%
Besides raising her viewer percentage from her later time slot, Greta Van Susteren, who took over Shep Smith's 6:00 pm slot, raised the ratings in his time slot too. Smith's 09/30 had 44.6% of viewers, and Greta has raised it 2 points to 46.9%.
Megan Kelly, who took over Sean Hannity's slot, raised ratings of the 9:00 pm slot 12 points, from 42.3% to 54.7%.
Sean Hannity, who took over Greta Van Susteran's slot, raised 10:00 pm ratings almost 6 points from 43.3% to 49.1%.
Bret Baier has seen a 2 point rise, and Bill O'Reilly gained 8 points.
Overall, Fox News has raised its prime time rating 9 points from 46.3% on 09/30 to 55.4% on 10/14.
The Fox News gain seems to have come from CNN as the senior cable news has dropped 10 points from 20.2% on 09/30 to 10.2% on 10/14.
MSNBC has stayed basically the same with a prime time rating loss of about half a point from 23.9% on 09/30 to 23.5% on 10/14.*
*The other 10% to 18% of prime time cable news viewers watch Fox Business Network, HLN or CNBC.
Update: 10/14 percentages have been corrected.