when the web was smaller spammers would operate their own spider (rather like Google) looking for possible email addresses (basically they looked for things like ab@nowhere.com addresses) - I suspect that with so many pages out there this is no longer feasible - much easier to get addresses wholesale by hacking into databases held by stores 9or even the ISP itself!) - or by persuading guillible people to download 'trojan' programs that transmit spam to those addresses in their address book - obfuscate your email address and all should be well.