sadiemae,
Mostly (I think) this group operates to share information about plants and their culture, share photos, help identify plants and keep up with botanical name changes, give recommendations of companies.
We also chit-chat about lots of stuff, share our joys and problems both in and out of the garden and sometimes there are 'not-a-raffles' where we can win valuable acorn currency, and if we get to silly our fearless leader Dave chucks us into the sandbox.
Some people do private trades, some participate in the co-op buys, and some are professionals selling plants and seeds.