[jlgreco]

You missed a biggy, which is "Receive bitcoins as payment".

You could set up a bitcoin gambling website, sell some sort of SaaS for bitcoins or, perhaps the most popular and profitable route right now, sell some drugs for bitcoins. Hypothetically, depending on your state/country, you could acquire weed legally and then (illegally) send the weed through the post in exchange for bitcoins.

[pyre]

You would have to provide it as a Tor hidden service though, otherwise all of your expenses in running the site would open the way for your anonymity to be breached (i.e. your domain name, your hosting provider, etc).

Basically if you're providing a service to someone, then there is a possibility of said service revealing who you are. E.g. if you're sending drugs to people, then maybe the packages are traced to a source.