Their original tagline was something along the lines of "it's preposterously easy to use." (I say it as "post-erous" too, don't worry).
"Post-erous, posterous, smackerous... They're too busy putting in new features to care about stuff like that. They care about results, not pronunciations. That's the start-up way."
(Unless of course it's Garry Tan trying to correct you on it.)