It's not just about joining Rotary, but participating in Rotary. There are many benefits to participating in Rotary:

1. Rotary makes your community a better place. My club, the Anaheim Hills Rotary Club (USA) provides funding to K-12 teachers, librarians, and other educators who might not otherwise be able to fund innovative ideas that complement traditional instruction.  Previous projects include school plays, science days, and hands-on projects that teach students about electricity or owl waste.
2. Rotary makes the world a better place. Rotary is most famous for its End Polio Now campaign. Over the past 30 years, End Polio Now has eliminated polio from all but three countries (Afghanistan, Nigeria, Pakistan) and has saved countless number of lives. There are many, many other smaller projects that have improved life in impoverished areas.
3. Rotary can make you a better person. The biggest benefit to me is that I've The biggest benefit to me is that I've met so many great people through Rotary that I may not have met otherwise. These are people that are smart, involved people that it's been my honor to know and work with. I have learned a lot from them.