Playing favorites is one of those things that just doesn’t sit well with me. It’s unfair to everybody else and the person being pandered to usually ends up with an inflated ego that’s going to pop sooner than later. All of this is to say that Facebook is the one playing favorites while Zynga’s head is slowly inflating. That’s at least what analyst and founder of Digital World Research P.J. McNealy is saying in his latest book, “Early Days: The Social Gaming Market And Facebook’s Achilles Heel.” USA Today did a quick run through the book and found some interesting insight into what Facebook is doing to marginalize its own gaming economy. Zynga is really important to Facebook . The social game developer provides a lot of revenue to the social media platform and in turn Facebook provides Zynga with perks. That’s a problem says McNealy because it’s leaving the other developers out of the loop.…