I think people are missing the point. It's the act of a stranger typing or writing the word "hon" (spelled just like that) to a female they don't know. It's like they're trying too hard to flirt, but looking stupid and pathetic.
Pet names (aka others mentioned previously) between a committed man and woman who are a couple doesn't apply in this case.
There are hundreds...
Just tonight on BitOG, I've again seen "I could care less about ... ," when the writer meant "I could not care less." Et cetera.---which many here inexplicably abbreviate as "ect."