It seems like it is scripted now instead of just an individual embellishment so I thought I'd throw it out to the FT community to see how common FAs add jokes during the safety briefing. I personally find it unnecessary and sometimes unprofessional.
Examples:

• Please at least pretend to follow along
• This is how you fasten a seatbelt as if you've never done this before in your life
• there are 50 ways to leave your lover but only xx ways to leave this plane
• Please secure your air mask first then assist any children or anyone acting like a child

I've heard them on United Express, Delta Connection, probably US Airways Express also. Mainly the express people, but I might have heard them on mainline too...like I said it is getting old and cliche.

How common is this routine and what are your opinions? What would the FAA think?