Last year, I was heading back to Florida on what was Spring Break getaway day for the GRR local K-12 school districts. I'm guessing 80%+ infrequent leisure travelers on the first leg because the FA on the GRR-ATL flight gave a 2-3 minute talk on the Skymiles program and why you should sign up, Delta miles never expire, etc. and there was surprisingly no mention of the co-branded AmEx credit card involved.
So there apparently are other targeted messages the FAs are encouraged to give.