Last Sunday's episode of FAMILY GUY was the 2nd lowest rated show during that hour on all 4 broadcast networks, beating only its follow-on AMERICAN DAD.
I dunno what else was on last Sunday. Lots of guys I know caught "The Walking Dead" season finale. Mrs. Lawson and I watched the season premieres of "Call the Midwife" and "Mr. Selfridge" on PBS. There also was NCAA men's basketball.
I'm gonna go ahead and say "Family Guy" is a success, given that it's aired more than 200 episodes over 14 years, and at any given hour, it seems to be in reruns on at least one of the channels in my cable package. And the creator is a young millionaire who makes movies and just hosted the Oscars.
Even held against the lofty Mike Bunge standards of success, surely you gotta show Seth MacFarlane a little love.