I created a comic with a friend after we were selected to be part of an Artists' Alley in a big Brazilian convention. We did everything in like a month and a half and it was crazy, but it was one of the happiest periods of my life.
When we were at the convention, sitting in a table between two much bigger artists (their tables were pretty packed, ours not so much, didn't really matter to us). We were approached by a girl on the first day (a Thursday) and she really liked our comic, but she didn't have cash and our credit card machine wasn't working at all this first day, so she said ''I'll be back Sunday and I'm gonna buy your comic, just you guys wait!!'' She was really happy to be there and it showed. She had a great energy.
We spent the next few days thinking that was an awesome thing and wondering if she was going to come back. She did, as promised, when Sunday was almost over. It felt great.
The whole convention was a really great moment. We sold like 30 copies of each of our comics in 4 days, but we loved every interaction. Both the comics we sold at the convention are here on Tapas and they're not good, but they have a lot of heart in them (: