It seems that Sprint got a bit too excited about its decent EVO 4G sales. It had originally stated that it sold 3x as many phones within the first day that their best phones had sold over 3 days. What it actually meant was that it sold in one day 3 days worth of phones. They double counted that triple multiplier it seems.
Regardless, they are sold out of the EVO 4G and analysts estimate that it sold a not too shabby 150,000 on launch. Nowhere near a 1 million unit iPhone kind of launch, but an achievement for Sprint and Android nonetheless.