I don't get it. They marketed it before the big IT 2 release, and I saw trailers and spots constantly during the CW superhero lineup, including the crossover. I saw trailers every day. I still see trailers. It's got ads on Twitter nonstop, and the cast did the typical talk show appearances. I get maybe thinking the marketing could have featured different stuff to hook some people, but it definitely got good exposure. I think people just weren't interested and that the title may have caused some confusion.
It was a film that no-one asked for, marketed to no-one in particular. In the end, it was little more than a vanity project for an actress who thought she could stamp her mark on a character who's appeal she did not understand, to an audience that did not exist. It's frankly as arrogant as Hollywood gets. Lessons learned for everyone with this.