I have cooperation with Optical Media. You can find them in Baidu search Optical Media. They have enrollment booths in Normal University, Heilongjiang University and Shanghai, and have deep cooperation in Harbin University campus. Toilet advertisements, stair corner billboards and wall advertisements are all primary resources. Guangyin Media is a college student company supported by black college students, so it has a unique internal advantage compared with off-campus advertising companies. At that time, I was putting up posters with him in colleges and universities in Harbin, planning audition classes and planning a series of publicity venues. The effect is still good. You can contact them to see.