As I read it, the novelty here is not so much the "computation" of content factor (which is really just total citations, in bite sized pieces, so to speak) but that this measure (whatever you want to call it) was shown to more strongly relate to importance of journals than does impact factor. Those are original data (at least for this domain. I think it was shown in other domains too).

Is it mere marketing to take total citations and chunk it into units whose magnitude more closely resembles impact factor, and then give it a name the somewhat resembles the name impact factor ("____T Factor")? Sure. But if it gets people to move away from impact factor, it is a plus, or, should I say, PLoS.