I have never attended an event, concert, protest, or volunteered my time based on ads. I have based on community event calendars, upcoming event calendars that while they may have taken money for placement (which they should have been required to disclose but probably didn't) had plenty of free listings. The main time I've used ads for 'things to do' is on vacation and have found the ad promoted stuff generally not a useful indicator and had just as good of luck with the service we randomly found on our own (thinking things like sailing/snorkeling excursions in Hawaii, Costa Rica).