Malthe Sigurdsson, from Skype, did a talk at Reboot 7 about how they built the brand and the basic principles behind their way of working: do simple things really well; release all the time (ie keep updating the application in small bites); evolve; open up; and viral features. A good illustration of the idea of simplicity is their preference for plain language – so talk about sharing and calls, not peer-to-peer and VOIP or telephony.
Skype has about 45 million registered users without advertising. People got to know the brand and functionality through word-of-mouth, nothing else. So it shouldn’t take long till the verb “to skype” will be as frequently used as “to google”, depending on how many users still adopt the software in the future and what the big telecoms have planned in order to compete.