This Christmas...A Diamond is Forever...
Jewelry companies aren't stupid. They know that Christmas is sweet and romantic...period. Therefore, they are not afraid to specifically mention Christmas, show a Christmas tree, etc., in their commercials.
I've already seen two Christmas commercials for jewelers, and we are not even at Thanksgiving! One was Kay Jewelers ("Every kiss begins with Kay"); while I'm not sure what the other one was, but it's motto was "A diamond is forever."
I'll note once again that mentioning Christmas isn't so much a risk as mentioning Christ's part in Christmas, but it is worthy of note anyway, although once the commercials start pouring in after Thanksgiving they might be impossible to keep up with.
~Kingdom Advancer