Just wanted to share some thoughts on the subject. A few year back we tried setting up a local seed exchange site, actually a subsite for already working and popular forums I happen to have co-started.

The main road block we met and that ultimately cancelled the project is most of the people didn't have the time, means or will to describe all the seeds the have to exchange.

Part of the problem was we wanted a nicely populated database so that meant families, species, varieties, characteristics and description of each one, preferably a photo. You understand how much more easier would that make a search or even a browse through the database.

However we got several of the most tech savvy people to use the site and they just created each a single item, inside listing all the seeds they have. And not at all descriptive! For example "6 varieties of cucumbers, 5 or maybe 10 tomatoes, a handful of beans", etc.

A bit frustrated, we (me and another guy that created the thing) tried using the system ourselves and input our seed stock. Well I have to tell you it took me 8 working hours just to sort through my seeds and make a basic plain text list of what I had. And I don't have this much seeds, just it's not sorted for presentation.

(btw that's the main reason I asked about the seeds listings the other day)

So we scraped the idea after a few months and that.

However, at a local seed exchange, real life whole weekend event, we saw a much better and natural way of doing stuff. People would just spill their goods on a blanket and others would browse and chat. Turns out most people don't really know what they're looking for and make spontaneous decisions based on names, dialogue or even type of seed package.

I fully understand that it's different for a business, but that's why I think there's a difference between social seed swap and selling seed. The two have very different models and UX and user behavior.