In case you’ve checked some of your spam mails recently you might’ve discovered how a large amount of them include links to sites using seemingly very random names in the domain names. Like hjsdhjerrddf.com or qwetyqfweyqt.com and so on. Hammering-the-keyboard looking names.
The explanation behind these is quite simple and sad: ICANN allows for a “tasting period” before you pay for the domain. Thus spammers register all sorts of random names, spam the world with mails referring the users to these domains and then they return the domain names again before they’ve paid anything, and go on to the next names.
With a large enough set of people and programs doing this, a large amount of names will constantly be kept in use but not paid for and constantly changing owners.
Conclusion: wherever there’s a loophole in the system, someone is there to exploit it for the purpose of sending spam.