I'm honestly surprised Cameo is doing as well as it is. To me, I personally find it sort of cheesy. I didn't purchase a Cameo or anything, but I did sign up on the service to see what it was like, and who all was on it. It seemed to be filled with quite a range of actors/actresses/celebs/etc. but since each of them were basically just reading a cliché "happy birthday" type script with insert {blank} name into the Cameo, it just felt disingenuous to me. A lot of actors also seemed to really "phone it in" for it. I was surprised how much people were paying for these, to be frank. If I received one from a friend, I just don't think I'd see the value, and I'm even a big tv/movie fan. "So, you just paid a celeb to say a few lines? Okay, neat, I guess?" I feel like it was probably more unique at the start when X friend didn't realize you had easy access to the celeb, so it felt like "OMG, how did you get them to do/say that?!" But now that it's getting more popular, it seems to me the value of it being unique would get washed out fast. ¯\_(ツ)_/¯
I think the best way for Cameo to actually expand would be to open it up to allow you to book a celeb for more than just a quick little video blurb. Like being able to invite them to parties, or events, and pay them for an actual true "cameo." It would obviously come with a price, but to me, that would be much more innovative.