Festival races
Many festivals include races or fun runs as event attractions. Few, however, offer anything to induce runners to stick around after the race.
At Race to Taste, a 5k in Chicago IL that preceeds the city's gigantic Taste of Chicago, runners are given free tickets that can be used at food booths before the Taste is opened to the public. In a previous year, the race offered free tickets for runners to ride the ferris wheel.
Typically, runners do not linger after races to attend festivals. They leave as soon as they've crossed the finish line, gotten food and drink, and learned their finish time (or collected their award).
If you want runners to stay, give them something tangible to keep them - free tickets or free food, for example. Don't assume the excitement of the festival will attract them - they didn't show up for that.
Also, many festival races provide little or no information about their runs. Despite clever themes and scads of activities, they offer no race details and post no links to registration sites.
Runners need to know about running events beforehand. Simply listing a race on a festival schedule is not sufficient.