A smart way of promoting your event is to go out with your flyers, discounts coupons, or any promotional material and hand them out to people as they are leaving at the conclusion of other events.
You can do this at concerts, Sporting Matches, Festivals, trade shows, network event, etc. One thing to keep in mind is to target events whose attendees are likely qualified to attend your events. Do it in group if possible, or recruit students crew to help out.
Imagine you have an upcoming business event related to marketing on Internet with search engines and social medias. You have heard about few small business networking events around town. If the event is interesting to you, attend it. At the end of the event, just stand a little bit far away from the venue gate and hand out your promotional material to people as they are leaving.