I helped organize a show as a benefit for the non-profit Women's Health Services program in my community. It's now in it's 3rd year. We have a pretty good turn out each year of both vendors and shoppers. We advertised in the paper (one ad, the week before the show), we did a radio show called "open line" which is free and various people schedule time to discuss things happening in the community on-air, we posted fliers around town, we put it on facebook, twitter, etc.... We sent out vendor packets to potential vendors well in advance with a flier, an app, and an invitation letter. We sent out post cards to a mailing list with the date and time, the program put "save the date" stickers on client paperwork from appointments. The program has a website, everything was put on there too. We partnered with a local grocery store to put "bag stuffers" into shopping bags when people checked out. Banners and balloons outside the event venue. Don't forget, if you organize, you are in charge of marking spaces, assigning vendors to spaces, renting venue, handling vendor issues the morning of and throughout the day (even if you are a vendor yourself), clean up afterward, etc. It was a very involved deal, but everything went very smoothly that day, and it's gotten easier each year. Make sure you've covered everything in the early planning stages and it can be very rewarding.