In a post on Reddit a guy did some work up front for free, assuming he was invited to the event the work was for. After finding out we he wasn't invited, he decided the work shouldn't be for free. Here's his story.
I own a printing company that I run with my wife. Her cousin came to us and wanted us to do all the signage, banners, guest books, life-sized cutouts, etc for her wedding.
We do this all the time for friends' weddings and events, and we never charge. We're happy to help out and it's usually a lot of fun working together to make some cool stuff.
A few weeks before the wedding, her wedding planner tells us they need all the items by X date so they can set it up for the wedding. At this point, we hadn't received our wedding invitations and didn't even know when the actual wedding was.