Run A/B testing to figure out most effective Instagram ads
Follow up with teachers, send more posters, reach out to clubs and programs, other hackathons who could promote
Possibly: reach out to closed sponsors, see if they want to promote event, share how their company/product is involved
Keep sharing on social media, hyping up event
possibly announce raffle or something for free swag? winners announced end of CodeDay. Give people a reason to click on the ad now vs save it for later