Do not be discouraged, 10% are very very very good numbers.
I work in other environments such as economy, marketing, ecommerce, app. An the numbers are way lower than that.
My percentages are 1% - 0,01% or even lower. Only 1 every 1000-100000 person make a trade. We got a lot of people that use our product and never make a trade. In your case 1 every 10 person make a trade back, so your numbers are amazing.
For example, if you enter the app market the numbers are much worse, you even have to pay for a user, imagine paying 10+$ for a user that install your app and you only get a trade less than 1% of them. Imagine applying that fairing to the case of seed swap. Paying 10$ for every seed packet and you only get a packet back every 1000 people.
And in the case of app you see that 80% of your new users just uninstall the app (let’s say the first week). So we are paying 50$ for users that got your app install more than a week. That is wild. And we have not even reached the worst cases or more competitive markets.
Just to give you an idea, paying more than 80$ for a click on a banner. It cost the company 80$ when a person click a link on an advert on a webpage. And you don’t know if they are going to make a trade.
I’m getting off topic, do you know the Pareto principle?
In the case of seed exchange 20% of your users will make 80% of the seeds for the swaps. And that’s fine and totally expected from human nature. Have you seen those numbers?
In my personal experience when I give away my seeds to people that do gardening or are starting gardening my rate of return is 5%, only 1 person every 20 gives me some seeds back.
If that were my worksheet, I would name the grexes or those starting varieties. You could even tell the group of people to do it. They would feel more involved in the process and it would be part of them. I would also adapt the names to the place where the exhibition or presentation was held.