Direct address commas are your friends, authors. They give important tags to dialogue, and their use, absence or misuse can mar your dialogue and be utterly distracting.
For example, “Let’s eat my dear.” Sadly, the dear is about to be dinner. While “Let’s eat, my dear” is an invitation to the sweetheart.
Similarly the command “Come on Chris” has Chris as the direct object pronoun. Whoever is being commanded is supposed to come on him/her (hope s/he consented!). While being exhorted, “Come on, Chris!” is much more innocuous: Chris is clearly the person being addressed.
I read a sample of a YA book which a reputable review site that I trust squee’d about. And the complete absence of DA commas killed my interest. It’s self-published and only $2.99 or $3.99, but I don’t think I can read an entire book full of dialogue that is missing DACs.
Yes, yes, call me fussy. But I think any editor worth his or her salt would have pointed out that some of the dialogue is incoherent without proper punctuation, and fixed it for the author.