How do you make your book memes and reading challenges more popular in the book community?

[Ronyell]

Hello! I'm Ronyell and I'm currently running a book blog called Rabbit Ears Book Blog. I also created the book meme Book Photo Sundays and now I'm hosting two reading challenges which are the Comic Book Bingo Challenge and the Caldecott Medal reading challenge.

I have been doing the Book Photo Sunday meme since 2016 and yet, I still haven't gained enough bloggers to participate. Also, for the Caldecott Medal Reading Challenge, even though I just posted this up recently, I still don't have any participants for the challenge.

How do I make my book memes and reading challenges more popular and how do I get more people to participant in them?