Have you ever wondered how much spammers make and how many spam emails are sent out? UC San Diego and the International Computer Science Institute wondered too, so they hijacked a botnet to find out. The team intentionally infected eight computers with a middleman virus, software they found that was relaying instructions between a botmaster computer and the network of computers it had secretly turned into spam-sending zombies. That is how many viruses work.
They changed the orders for their own research. Instead of sending people to the botmaster’s website, spam ads instead funneled them to a site built by the team. It looked like an authentic Internet pharmacy, but didn't take orders, it just gave an error message. The team used the info to calculate an estimate of how much money the spammer grossed per day.
Interesting statistics from the spam experiment - 23.8% of messages were actually delivered, of those, .0127% of people responded, and 2.66% went to the site to buy something for an average price $100. In all, they infected just 550 PCs which each sent out an average number of 1.7 million emails per day. The average daily take was about $7,000. Annual take $2.55 million.
Considering that spammers infect much higher numbers of PCs and some mail out many more than 1.7 million messages, and they do it 7 days a week, it begins to quickly add up. If you just did five times that amount, it comes to $12.8 million a year. Not too bad for a few lines of code and letting all the others do your mailing.