Putting aside whether I believe this is accurate or not momentarily, look at these conversion rate. 1% Response rate for unsolicited direct mail ('spam' - heck

Putting aside whether I believe this is accurate or not momentarily, look at these conversion rate. 1% Response rate for unsolicited direct mail ('spam' - heck, I used to have that response rate doing real estate direct mail with actual letters!) 5% Conversion rate from responders to 'clients' Average 'sale' $7,500 So 100,000 spam emails generate 100 responses, which is 5 'clients' and $37,500 in revenue. Return per email is 37c - with a negligible cost to harvest and send it's little wonder my spam filter works so hard.