Basically, I think a good way to encourage members of the site to read more political theory would be to put some kind of marker on their profile or next to their name that shows how much and what kinds of political theory they have read. I also hope this would have the secondary effect of allowing lurkers who see disagreements to get a better feel of which side has a stronger basis for their position.
Maybe something simple like marking which accounts participate in the weekly reading series, and make it a riff on challenge coins or something.
Edit: I should specify that it would be awarded to people that are participating in discussion groups and such as a way to signify who is involved in the education side of the community.
Edit 2: Fuck It, I have been convinced that this is a bad idea. Instead how about a weekly what are you reading thread?
If you want people to engage with theory, don't shame them by making it a public competition over who's read the most. Use the carrot instead: quote the most interesting, fiery, and relevant bits - relevant in the sense that they can speak to people's experiences on the ground and at their current level of understanding. I have a lot of success with :graeber: because he's both very gripping and very accessible.
When people bring up opinion polling, or the Sanders/Corbyn losses, as expressions of the democratic will of society (they lost! get over it) I like to hit them with this little bit of text about how various channels shape and constrain public opinion. On automation, I pull up this lovely quote that helps highlight how much labour is actually caring labour. If you're feeling dejected about revolutionary potential, this essay is a good remedy.
Honestly I didn't even consider it as shaming them. I figured it would just be a nice way to note who is involved in the discussion. Regardless, this is good advice.