I've been to many, many weddings of people I did not know at all. I was the oboist in a woodwind quintet that was in the business of providing background music for such events. We promoted ourselves fairly heavily, appearing at wedding planning seminars and shows and playing in the background there, with our business cards available, of course.
So, for about eight years, I often had to don my tux and show up to make music for the celebrations. Sometimes it was just the reception, but we also played at the weddings themselves fairly often. When someone was considering hiring us, we'd just invite them to one of our weekly rehearsals and play music for them and chat with them to figure out what sort of music they'd like.
Weddings are fun. Somebody's celebrating a happy event. We were always surprised that most often, we ended up being treated almost as guests at those receptions, despite the fact that we were getting paid pretty well for showing up to play. Everyone's in a good mood at weddings, and the band gets champagne, too.
One time, we even played at a very fancy wedding in Balboa Beach, CA, down near San Diego. It was a rare road trip for the group, and our expenses were added to our fee. Oddly enough, nobody in the quintet knew the bride or groom. We never did figure out how we got hired for that. Our best guess is that the bride or groom or both had attended a wedding we played at. Fun times.