Dear Miss Snark,
This question rises from the depth of the other 90%. Those of us who are story-tellers rather than wordsmiths and try as we might will probably never write the gin-pail dropping query.
What if one of us poor slobs was to self-publish a novel, promote it on a web site and sell impressive numbers (insert own scornful number here.) Would you consider taking on another work by such a person with only that as a credential?
Before you cut & paste advice 3-C, (get off buttocks and do your time with magazine articles) let me be irritating and say that some of us feel that the qualities make for short articles are not the same as those needed to create a MS that doesn't have a serial killer or a shiny-toothed cop chasing an evil drug-lord.
My retriever says hi to KY and wants to know if he's up for a rabbit-hunt sometime?
First, KY wants to know if he has to bring firearms for a rabbit hunt. Sadly, his application for a concealed weapons permit was denied by NYPD. Something about his "known associates" being of questionable character.
Second, I'll consider anything you send me that's well written. You can write and self publish a great novel and sell ten zillion copies. I still won't consider it a writing credential, but it doesn't mean I won't read your second work.
If you write well, I'll read it. You can be unpublished, multi-published, published exclusively in Rabbitania, and looking to break into the North American market: if you write well, I'll read it. If I think I can sell it, I'll talk to you. If you aren't a nutcase, and I'm not swamped with projects, I'll probably invite you to the dance.
Publishing credentials are nice, but it's the writing that counts.
Once more with fervor: good writing trumps all.