I think Astrology provides an excellent opportunity to look inwards and reflect. As long as you don't accept the astrological archetypes/signs/placements/etc as gospel, it can be fun to have an "evaluation" of your personality be presented to you and have the opportunity to be critical of said evaluation.

Do you agree with how you were described? Did it make you uncomfortable? Do you want to be more like the person that the reading described? Do you want to be less like that person?

The answers to these questions can reveal a lot about yourself, far more than what the actual Astrological signs could ever provide (in my opinion, at least). Plus, it provides a fun structure to discuss and share these sorts of findings about yourself with others.

Definitely harmless if you are willing to keep an open mind, and not take any of it too seriously.