Martin Schneider writes:

In the most recent episode, "Ho Ho," the wealthy scion of a shipping magnate (himself a friend of Bertram Cooper) hires Sterling Cooper to ensconce jai alai and el rey de la pelota—identified as "Patchy"—in the lucrative embrace of the American mass.

Somewhat improbably, Don is opposed to the account, as it will take advantage of a well-connected dupe. Upon hearing Don's well-meant advice to drop the project, the scion intones, "If Jai alai fails, it's your fault." (James Wolcott cracks, "A heavy burden to lay on Don, or any man.")

Considering that eleven years later, Herbert Warren Wind would be taking up the quixotic project to introduce Basque pelote sports to New Yorker readers, it's safe to assume that jai alai never takes off.

Sorry for spoiling future episodes!

Relatedly, if you look at page 24 of the October 12, 1963, issue, there's an advertisement for Florida that mentions jai alai. While far from a masterpiece, it does look considerably more modern than the stuff we see Sterling Cooper putting out. Time to step it up, boys (and Peggy).