If I were a game runner I would be pretty leery of paying for a service like this. Or even participating in something more similar to groupon for games, after seeing how having an influx of clients that you didn't anticipate and could not accommodate at the pace that they expect can impact a business in RL.
I get how this might be an attractive business venture for the people arranging it, but there are just a lot of consequences for increasing volume that a lot of people do not think about.
The rush and influx of people who come in to create new bits and join a game even when it's just advertised here can be a game killer, especially after the 6-8 weeks for the new shiny to wear off and people wander away or get mad that they aren't being entertained as much as they think they should be, especially if staff was excitedly running a lot of stuff at first but then quickly burnt out by needs and wants of a population that was double or more what they planned for. Or people get super excited and run a bunch of stuff until the novelty wears off and then disappear, which can make others feel like the game is suddenly "dying" when in fact it's just that the super active RP/scenerunners burned out quickly and there was a mistaken impression of the /base/ activity level of the game.
I just do not think you'll have enough buy in from game runners in order to monetize this. (Note, I'm not saying it's wrong to monetize your work or your coordination.) I think maybe if one wants to expand access to MUing then the focus should be less at first on finding players and more supporting and empowering game creators/runners, to expand the number and diversity of offerings first, because otherwise you're likely to decrease the quality of the experience if you stuff 3x more people into the same games.
To that end I think stuff like Ares that puts the ability to run a game into more diverse hands in a plug and play format does much more to help sustain MUing than advertisements on social media.