I would say *especially* if you live on an island, or any other isolated or remote community.

For one thing, there isn't a flood of posts to wade through. For another, people are pretty good about describing objects accurately and reliably coming by to pick them up - while it's not literally true that everyone knows everyone else, it's easy to see that word gets around if problems come up.

I was on the Seattle freecycle list for a while, helping someone else pass on gardening excess. We were not successful, and I signed off as soon as I could.