With Bill O'Reilly on vacation and maybe never returning, others have been filling in. 

So how are they doing ratings wise?

Not good. 

FNC replaced O'reilly with three different hosts each night. Dana Perino, Eric Bolling and Greg Gutfeld all took turns filling in on the Factor. 

The numbers show Bolling did the best, with his 3.11 million viewership.

The show took a big hit with Gutfeld last Friday. The numbers were down 39 percent from the previous Friday, to just 2.32 million. 

Of course, when compared to CNN and MSNBC the numbers are still strong and leading the time slot. But, it shows that Fox News will have to be very careful in picking a replacement if they decided to give Bill the boot.

Stay tuned....