Yes! It can happen! And I am thrilled that it happened to such an awesome author! In fact, I'm so full of thrilled it's spilling out in an abundance of exclamation points!
Many of you may remember Chelsea Pitcher from her queries and invaluable advice here and at Evil Editor's place. Last June, we toasted to Chelsea having picked up an agent who picked her up from the slush pile. You'll find the query that won the agent over at that link.
And now I get to announce that Chelsea has a book deal with a Simon & Schuster imprint! Here's the news straight from Publishers Marketplace (note some of the links will only work if you have a paid subscription).
Chelsea Pitcher's THE S-WORD, pitched as The Scarlet Letter meets Veronica Mars, about a high school girl who found her best friend in a compromising position with her own boyfriend on prom night and cut off their friendship, then was plagued by guilt and decided to find out who was responsible after her best friend was branded Queen of Sluts and committed suicide, to Adam Wilson at Gallery, in a nice deal, for publication in 2013, by Sandy Lu at the L. Perkins Agency (World).