"Merry Christmas" EASILY outsells "Happy Holiday"
Should you write Merry Christmas or Happy Holidays on cards? That’s a personal choice, but if you are into selling, then ConversionVoodoo claims that their large A/B test results in “Merry Christmas” converting way better:
As you can clearly see, “Merry Christmas” killed it, nearly doubling the click through rate of the other subject lines. 5.47% vs 2.90% is a clear winner with statistical confidence.