Simply put: It means "okay" or "alright" or "i understand".
More specifically it's used in closing of a conversation or topic. "kkies" I understand and do not need further clarification. "kkies" I got it.
May be used as an acknowledgement of the closure of a conversation. Indicates that that a future conversation will be held, similar to "talk to you later" or "ttyl".
1: Well Imma go watch MTV now.