Oh man, get out of my head. Rotary and BNI are two of my favorite orgs!
My Rotary Club might not be typical so take this with a grain of salt but it is the best place to meet the Movers and Shakers. You have to be either a business owner or in a management position to join and they do some amazing work in the community. When I was growing my web design business I started doing some free work for local non-profits. It was great for building my portfolio and it lead to plenty of paying work. And then I was invited to join Rotary and that opened up a whole new world of opportunity.
I was also a founding member of my local BNI chapter and attribute a great deal of my success to that group. But I'm no longer a member because it is a huge time commitment and the more business it brought me the less time I could commit to it. On top of that, there is a lot of pressure to pass referrals to each other and for a web designer who doesn't do a lot of sales calls that was very difficult to keep up. People that do exceptionally well in BNI are folks who work in real estate or who spend most of their time in sales.
The common thread between both of these groups though is referrals. I don't go to a Rotary meeting or a BNI meeting with the objective of trying to sell my services to another person in the room. I put in the time with these groups because when they leave that meeting I want to be the first person they think of when they hear someone is looking for my services.
For our hypothetical florist, Flo, these are great routes. Just like you used to go to meetups to share knowledge with fellow professionals, she needs to build relationships with people who are not her competitors but share some of the same customers. A wedding planner, for example, would likely want a reliable florist to recommend to her clients and vice versa.
Funny Story: In our BNI chapter the wedding planner, the baker, the caterer, and the florist always sat together and were referred to as the "Wedding Mafia". They never had any trouble coming up with enough referrals for each other,