NB As noted in the comments to this answer, and in the other answers, the answer below does not reflect the current procedure. Leaving this for the historical record.
It seems like the CC3000 is actually listening (in "promiscuous mode") on all wifi channels for an AP probe request, the probed (and fake) AP's SSID containing the information that the CC3000 requires to configures itself to connect to the "true" AP through which it will connect to the Internet.
After searching a bit, I found this description of the device's first time configuration which should make it clear:
http://processors.wiki.ti.com/index.php/CC3000_First_Time_Configuration
Most interesting bit:
A device such as a mobile phone or tablet used for performing a first time Configuration needs to be configured to connect to an AP with a specially crafted SSID. This SSID includes the name of the SSID to which we want the CC3000 to connect, as well as information about security options such as security type and key.