Sans ouvrir la bouche - without saying a word.
The Francophile likes to surf the web. On French TV, at BFMTV, he came across this article about the former (ancien) president of France, Nicholas Sarkosy.
"Sur Facebook, Sarkozy "occupe le terrain sans ouvrir la bouche."
Literally, the the sentence translates at "On Facebook, Sarkozy occupies the ground without opening the mouth." A better translation is "On Facebook, Sarkosy wins the day without saying a word."