I'm possibly wrong, but for me, Merry Christmas has a direct association with buying, sales, or e-mails about a sale etc., while happy holidays doesn't conjure

I'm possibly wrong, but for me, Merry Christmas has a direct association with buying, sales, or e-mails about a sale etc., while happy holidays doesn't conjure up the same meaning, and hence a higher probability of me opening an e-mail? Maybe fewer percentage of the people even opened the e-mail and the click-through percentage of the people that actually opened the e-mail was the same?