It's a good option, but it's something that not everyone will like, so it's best to leave the ads as they are. And I think an alternative would be the signature campaign that already exist, like the one I'm using. If you want to promote non-profit projects, you can use them, but I think using ads is unnecessary at the moment.
So much what I had to say.
Every account has a space for signature. If anyone wants to promote a non profit projects, they can use their signature or better make a thread for it, people can voluntarily wear the signatures.
I can tell you that the signature you are wearing has more visibility than some paid signatures due to the influence of the campaign manager behind it. I also have seen signatures like cleanupbitcoin that people wear for free.
I just think that theymos wants the signature space to be the only ad space since he announced that the forum needs no more donations or money from ads. I read where theymos promised to give Talkimg of joker a free publication with the ad space in the early time of the project. Did it happen?