Indeed, if 98 ultimately scored a higher rating with Christmas than without--none of us knows--then it is a win, whether that win is up over the previous book or not. I was just throwing out one possibility among many as to why their best-case scenario could have been to minimize defections as opposed to actually going up.
And some of the flip sides of why folks liked Now better is why some like the B better. For me, if I'm going to hear Rockin Around the Christmas Tree approximately 2,941 times, then as much as I want Brenda Lee to be part of the mix, I want some other versions, too. Likewise, I like hearing some of the same artists doing the Christmas songs as are in the 'regular' format a bit more. (Though I'd rather never, ever hear the Hippo song so long as I live...there's a special place in hell for whoever unleashed that thing on humanity ;D.)
Given "doing the format well" is highly subjective, it's unlikely we'd all agree on the concept. From a business standpoint, knowing that you can't please everyone--and trying too hard will likely please almost no one--the question becomes which approach you take and what's best for your business.
And one thought...if the B 'steps up its game' so to speak next year and plays the format in a way that's more to the liking of the Now fans, will that mean they automatically get blamed for being copycats? (As in, they're damned if they do, and damned if they don't.) ;D