Hi skora,
I see Nick jumped in here, but since this is already composed, I’ll post anyway.
Code for BTV had an exhibit at this year’s Champlain Mini Maker Faire, held in September in Shelburne, VT (just south of Burlington). There was no charge for the booth, as we are a non-profit (for purposes of reporting to the IRS, our brigade is affiliated with another local 501c non-profit). 5 volunteers from the organization were given free admission.
Champlain Maker Faire is a franchise of a larger organization, which really helps them with organization. They did a good job at publicizing the event, so attendance was good. In their vendor application they asked all the right questions: how much power do you need, do you need Internet, will you be making a lot of noise, etc. The faire is run by volunteers, so some information wasn’t provided until the last minute, but we’re also an all-volunteer organization, so that wasn’t a surprise.
The daytime session when we exhibited ran for 5 hours. We had a small banner on the wall behind us. On the table we had printouts about each software project (planned, active, complete), and stickers with the Code for BTV logo. We had a slide show about Code for BTV/Code for America that displayed on a large-screen TV (we can share, if you’re interested). We had a brochure that explained how members of the public could get involved in a simple Civic Tech project, Humanitarian OpenStreetMaps.
(in lieu of our yet-to-be-completed blog post)
The first hour was slow, because we were located at the back of the venue, and it took a while for people to make their way to that area. I’d guess we engaged with about 50 people, including businessmen, hobbyists, teachers, children, and professionals with a technical background. There were more who browsed, but didn’t stop to chat. Out of the 50, there were about 10 who expressed an interest in volunteering for Code for BTV at some point in the future. We gave technical advice to someone who had a specific civic project in mind that he wants to do on his own. We gave advice to young people (middle/high school) about ways they could learn to code at home. Several teachers took the brochure and expressed an interest in having their students participate in map creation. As we were packing up, we were approached by the mayor of Montpelier (a city about 50 miles away with a small but growing tech community), wanting more information about our brigade.
It helped that we were between two popular booths, a high school robotics team and an organization that allowed people to fly drones. We considered scheduling a session to teach people how to get started with HOSM; maybe next year. 
We should have allocated time before the event to set up demos of the apps and let the volunteers become familiar with using them. The faire organizers emphasized that interactive exhibits were more popular, and that seemed to be true.
This particular faire has both indoor and outdoor exhibits, so attendance is highly dependent on the weather. You might be able to find out more about your local faire by asking people who belong to maker spaces in your area. Overall, we thought the time spent on the exhibit was worth it, and will probably have one next year, too.
Best wishes,
Christina