The site has 24k active users. Do you think it's impossible that 7.6k of them have the archive option of $25/year enabled? I have no reason to doubt this, archive feature is great and supports the service.
English is not my first language, so I'm not sure. Does "makes $200K every year" mean net profit or just the income from which hosting still has to be subtracted from? If it's the latter, that means a lot more people are paying for archive.
The link is for 2012, but they haven't changed much.