After adding your race, be sure to +1(plus one) it on Google. The Google+1 is at the top left of every event. The number of people who +1 your race will tell Google how popular your race is and can determine your place in Google search pages. Adding comments, results and content to your event page also helps.

Comments can be about running your course, different peoples PRs on your course and how likely a PR is. Any thing relevant to running your race or even planning the course can be a good comment which will bring visitors to your event page