Hi Jo! I've been wondering, how often should a dancer change her act? I've seen dancers do the same act over and over for years, but I feel pressure to always present something new.
It depends! It depends on the performer and his or her goals, on the venues they're in, etc.
I have to say, I love to see someone repeat an act. Sometimes I don't realize how perfect an act is till I've seen it a few times. I could watch Bambi the Mermaid do her chicken routine another hundred times.
I think you HAVE to add numbers to your repetoire, but with care rather than urgency. I'm not a fan of ALWAYS doing something new because then the acts tend to be under developed. It depends on the venue though--if it's a weekly show, it can be fun to present new things that haven't required a ton of work but have great playful energy. However, people always ask me what big festivals and pageants are seeking, and they are seeking developed performers with finished routines.
At a high level of production, it can take over a year to put one act together. Immodesty Blaize is not doing a new act every weekend, and she gets flown all over the world to perform.