Billy Corgan and Jimmy Chamberlin formed Zwan back in 01, after Smashing Pumpkins disbanded.
Here is a screenshot of what Zwan.com looked like in 2002,
They were using the name ZwanMusic.com originally and then started using Zwan.com. The band only stayed together for a couple years and by 03 they were done.
It looks like in 2004 that Billy Corgan started forwarding Zwan.com to BillyCorgan.com.
That continued for a couple years and then it was used to promote the new Smashing Pumpkins album as they got back together.
Zwan.com expired and NameJet secured $601 for the name back in August of 2008. A year later the name sells on Sedo for $15,350. The name was parked at Sedo and went under privacy. There is one time where the privacy was not showing and it looks like the registrant was a consulting firm out of Colorado. Looking at other names they own, Zwan might have been a surname.
Well the name was left to expire and closed at DropCatch on Sunday for $3,050.