Sometimes used by people who mean to give a kiss goodbye during an IM convosation. Put when someone isn't sure whether to put just 'cya' or a proper 'cya xxx' so they combine them. Making the kiss look like a possible accident.
Guy: "ok bye then,"
Girl: "kk, cyax" (signs off)
Guy (thinking): "wait, was that 'cya x' or just 'cya' hmmmmmm"