I also have an interest in NYC->SXM, though it's not MR friendly, so I find myself more concerned with the fare rather than CPM. US runs a daily flight through CLT and UA runs a seasonal flight IAD->SXM on Saturdays until 2/14 and on Saturday & Sunday thereafter.
Outside of *A, I'm considering Jet Blue's direct, which had a $99 each way fare offered during their Black Friday sale. I don't expect to see that fare during the season, but I'll probably bite if the dates work for me and it comes in under $350.