Also lead with the location, like {City} locals. solve the main objections: why would people even try jiujitsu. 99% of people don't even know what it is. most people are intimidated, and don't want to do something that's tough. the audience is mostly problem aware, so you have to make them solution aware: they are trying to get fit and lose weight while learning self-defense and building up confidence and mental strength. they don't know jiujitsu can do that for them. they have probably tried working out at the gym and it didn't work. lastly, I would say plug in the challenge as the mechanism which is pretty solid. but dont lead with the anniversary or the challenge. I would say something like hey {city} locals, tired of (pain/problem). tell them it's not their fault. talk about why the gym or other fitness methods are not effective, and talk about how you can help them with your jiujitsu challenge, then you can plug in what they will get out of the challenge and answer main objections (safety, intimidating, etc). then call to action.