From the same comments trail of Joe Konrath's blog comes this comment by e.c. morgan, who once worked as an editor at an automotive magazine:

Persistence is important in this business. I remember one writer who sent me query after query. I'd reject one and he'd immediately send another. All were well written, very professionally done — he was just barely missing the mark. Finally, after about a dozen rejections, I sent an assignment for a different story back with the rejection slip (his query was similar to a story we already had in the works). Seven years later, when I look at that magazine at the store, I still see his name in there.

Never, never, never give up (to paraphrase old Sir Winston). 🙂