I've heard one of the ways to increase your spam load is to post your email address on a website, and anecdotally I can vouch for that. For example, just recently I've started receiving spam addressed to message IDs of emails I posted to public mailing lists. So I decided to quantify that a little bit. To that end I have sprinkled some new email addresses around on my website and carefully noted where. Over the next few weeks, months, however long it takes, I'll watch the results and let you know.