Wired News: Antispam Companies Raking It In
Recent estimates from the Radicati Group show that firms selling antispam products and services stand to make $653 million in revenues in 2003, and up to $2.4 billion by 2007.

In comparison, spammers overall will make between $11 million and $111 million this year, an estimate derived by comparing the number of known spammers with the range of their incomes as reported in public interviews.