>>534328718
In general, any character that has a higher average % of porn is secondarybait. This isn't to say that all Asuna or Rio fans are secondaries, but rather people from outside the fanbase are more likely to be interested in them purely for sexual reasons. Characters like Rio, Hasumi, Asuna, Karin, and Toki get a lot of artwork, but a great chunk of it is pornography. It creates a feedback loop where the art that circulates the most is porn due to secondary appeal, which encourages artists to make more porn, etc.

C&C in general is basically just the secondarybait club.