Many many moons ago, I wrote a quick article for Writing for Dollars called The Rule of 13. I'd heard that having 13 queries or submissions out at a time is a sure way to get an acceptance.
I know now there is no real magic number. Thirteen, however, is a better odds than six, not as good as 25. Thirteen, for most beginning writers, is manageable. The important thing is making sure your letters, your name, is in front of editors. The more you market, the greater the chance of getting a YES.
Anyway, I found out this week that our articles archived on WFD will now be drawing income depending on the readership. I was already paid when I printed the piece, so this is a nice little bonus.
An even nicer bonus, when I sent an email to the editor to update my bio info, he wrote back to tell me that he always liked that piece and recommended it frequently. It was a nice boost to an otherwise crappy day.